Asus B250M-A User Manual

PRIME B250M-A

Motherboard

E11969
First Edition

August 2016

Copyright © 2016 ASUSTeK COMPUTER INC. All Rights Reserved.

No part of this manual, including the products and software described in it, may be reproduced,
transmitted, transcribed, stored in a retrieval system, or translated into any language in any form or by any
means, except documentation kept by the purchaser for backup purposes, without the express written
permission of ASUSTeK COMPUTER INC. (“ASUS”).

Product warranty or service will not be extended if: (1) the product is repaired, modied or altered, unless
such repair, modication of alteration is authorized in writing by ASUS; or (2) the serial number of the

product is defaced or missing.
ASUS PROVIDES THIS MANUAL “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS

OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OR CONDITIONS OF
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This product contains copyrighted software that is licensed under the General Public License (“GPL”),
under the Lesser General Public License Version (“LGPL”) and/or other Free Open Source Software
Licenses. Such software in this product is distributed without any warranty to the extent permitted by the
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Where the applicable license entitles you to the source code of such software and/or other additional data,
you may obtain it for a period of three years after our last shipment of the product, either

(1) for free by downloading it from http://support.asus.com/download
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In your request please provide the name, model number and version, as stated in the About Box of the
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The source code will be distributed WITHOUT ANY WARRANTY and licensed under the same license as
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ii

Contents

Safety information ...................................................................................... iv

About this guide ......................................................................................... iv

Package contents ....................................................................................... vi

PRIME B250M-A specications summary ................................................ vi

Chapter 1 Product introduction

Motherboard overview ............................................................................. 1-1

Central Processing Unit (CPU) ................................................................ 1-8

System memory ........................................................................................ 1-9

Chapter 2 BIOS information

BIOS setup program ................................................................................. 2-1

EZ Mode ..................................................................................................... 2-2

Advanced Mode ........................................................................................ 2-3

Exit menu ................................................................................................... 2-4

Appendix

Notices .......................................................................................................A-1

ASUS contact information .......................................................................A-5

iii

Safety information

Electrical safety

• To prevent electrical shock hazard, disconnect the power cable from the electrical outlet

before relocating the system.

• When adding or removing devices to or from the system, ensure that the power cables
for the devices are unplugged before the signal cables are connected. If possible,
disconnect all power cables from the existing system before you add a device.

• Before connecting or removing signal cables from the motherboard, ensure that all
power cables are unplugged.

• Seek professional assistance before using an adapter or extension cord. These devices
could interrupt the grounding circuit.

• Ensure that your power supply is set to the correct voltage in your area. If you are not
sure about the voltage of the electrical outlet you are using, contact your local power
company.

• If the power supply is broken, do not try to x it by yourself. Contact a qualied service

technician or your retailer.

Operation safety

• Before installing the motherboard and adding components, carefully read all the manuals
that came with the package.

• Before using the product, ensure all cables are correctly connected and the power
cables are not damaged. If you detect any damage, contact your dealer immediately.

• To avoid short circuits, keep paper clips, screws, and staples away from connectors,
slots, sockets and circuitry.

• Avoid dust, humidity, and temperature extremes. Do not place the product in any area
where it may be exposed to moisture.

• Place the product on a stable surface.

• If you encounter technical problems with the product, contact a qualied service

technician or your retailer.

About this guide

This user guide contains the information you need when installing and conguring the

motherboard.

How this guide is organized

This guide contains the following parts:

• Chapter 1: Product introduction

This chapter describes the features of the motherboard and the new technology it
supports. It includes descriptions of the switches, jumpers, and connectors on the
motherboard.

• Chapter 2: BIOS information

This chapter discusses changing system settings through the BIOS Setup menus.
Detailed descriptions for the BIOS parameters are also provided.

iv

Where to nd more information

Refer to the following sources for additional information and for product and software
updates.

1. ASUS websites

The ASUS website provides updated information on ASUS hardware and software
products. Refer to the ASUS contact information.

2. Optional documentation

Your product package may include optional documentation, such as warranty yers,

that may have been added by your dealer. These documents are not part of the
standard package.

Conventions used in this guide

To ensure that you perform certain tasks properly, take note of the following symbols used
throughout this manual.

DANGER/WARNING: Information to prevent injury to yourself when
completing a task.

CAUTION: Information to prevent damage to the components when
completing a task

IMPORTANT: Instructions that you MUST follow to complete a task.

NOTE: Tips and additional information to help you complete a task.

Typography

Bold text Indicates a menu or an item to select.

Italics

<Key> Keys enclosed in the less-than and greater-than sign

<Key1> + <Key2> + <Key3> If you must press two or more keys simultaneously, the key

Used to emphasize a word or a phrase.

means that you must press the enclosed key.

Example: <Enter> means that you must press the Enter or
Return key.

names are linked with a plus sign (+).

v

Package contents

Check your motherboard package for the following items.

Motherboard

Cables

Accessories

Application DVD

Documentation

ASUS PRIME B250M-A motherboard

2 x Serial ATA 6.0 Gb/s cables

1 x I/O Shield
1 x M.2 screw package

1 x Support DVD

1 x User Manual

If any of the above items is damaged or missing, contact your retailer.

PRIME B250M-A specications summary

LGA1151 socket for 7th / 6th Generation Intel

and Celeron® processors

CPU

Chipset Intel® B250 Chipset

Memory

Expansion
slots

Graphics

Storage

Supports Intel® 14nm CPU

®

Supports Intel

* The Intel® Turbo Boost Technology 2.0 support depends on the CPU types.
** Refer to www.asus.com for Intel

Turbo Boost Technology 2.0*

4x DIMM, max 64 GB, DDR4 2400 / 2133 MHz, non-ECC, un-buffered memory*

Dual-channel memory architecture

Supports Intel

* DDR4 2400MHz memory frequency is only supported by 7th Generation Intel® processors.
** Hyper DIMM support is subject to the physical characteristics of individual CPUs. Please

refer to Memory QVL (Qualied Vendors List) for details.

®

Extreme Memory Prole (XMP)

1 x PCI Express 3.0/2.0 x16 slot (@ x16 mode)

2 x PCI Express 3.0/2.0 x1 slots
Integrated graphics processor - Intel® HD Graphics support

Multi-VGA output support: HDMI, DVI-D, D-sub ports

- Supports HDMI 1.4b with maximum resolution of 4096 x 2160 @24Hz / 2560 x
1600 @60Hz

- Supports DVI-D with maximum resolution of 1920 x 1200 @60Hz

- Supports D-sub with maximum resolution of 1920 x 1200 @60Hz

Maximum shared memory of 1024MB

®

Intel

B250 Chipset

- 1 x M.2_1 Socket 3 with M key, type 2242/2260/2280 storage devices support (both
SATA & PCIE 3.0 x 4 mode)*

- 1 x M.2_2 Socket 3 with M key, type 2242/2260/2280 storage devices support (PCIE

3.0 x 4 mode)

®

- Ready for Intel

Optane Memory**

- 6 x SATA 6.0 Gb/s ports (gray)

®

- Supports Intel

* When M.2 Socket 3 is set to SATA mode, SATA port 1 is disabled.

®

** Intel

Before using Intel® Optane memory modules, ensure that you have updated your
motherboard drivers and BIOS to the latest version from ASUS support website.

***These functions will work depending on the CPU installed.

Smart Response Technology***

Optane Technology is only supported when using 7th Generation Intel® processors.

®

CPU support list.

(continued on the next page)

®

Core™ i7 / i5 / i3, Pentium®,

vi

PRIME B250M-A specications summary

LAN

Audio

USB

ASUS unique
features

Realtek® 8111H Gigabit LAN supports LANGuard

®

ALC887 8-channel High Denition Audio CODEC

Realtek

Gaming Audio:

- LED-illuminated design: Brighten up your build with the gorgeous illuminated
audio trace path

- Audio Shielding: Ensures precision analog/digital separation and greatly reduces
multi-lateral interference

- Dedicated audio PCB layers: Separate layers for left and right channels to guard
the quality of the sensitive audio signals

- Premium Japanese audio capacitors: Provide warm, natural and immersive

sound with exceptional clarity and delity

- Supports Jack-Detection and Front Panel Jack-Retasking

®

B250 Chipset

Intel

- 1 x 5Gb/s USB Type C port supports 3A power output (at back panel)

- 4 x USB 3.0/2.0 ports (2 ports at mid-board; 2 ports at back panel, blue, Type

A)

- 6 x USB 2.0/1.1 ports (4 ports at mid-board; 2 ports at back panel)

ASUS 5X PROTECTION III

- ASUS SafeSlot Core - Strengthens your slot and DIMM pins

- ASUS LANGuard - Protects against LAN surges, lightning strikes

staticelectricity discharges!

-

ASUS Overvoltage Protection - World-class circuit-protecting power
design

- ASUS DIGI+ VRM - 5 Phase digital power design

- ASUS Stainless-Steel Back I/O: 3X corrosion-resistance for greater durability!

Superb Performance

M.2 Onboard

- The latest transfer technologies with up to 32Gb/s data transfer speeds

ASUS EPU

- EPU

UEFI BIOS

- Most advanced options with fast response time

Gaming Scenario

Audio Features

- Audio that roars on the battleeld

ASUS Exclusive Features

- ASUS AI Charger

- ASUS AI Suite 3

(continued on the next page)

vii

PRIME B250M-A specications summary

EZ DIY

UEFI BIOS EZ Mode

- Featuring friendly graphics user interface

ASUS unique
features

ASUS Quiet
Thermal
Solution

Rear panel I/O
ports

Internal
connectors

BIOS features

- ASUS CrashFree BIOS 3

- ASUS EZ Flash 3

Q-Design

- ASUS Q-DIMM

- ASUS Q-Slot

Quiet Thermal Design

- ASUS Fan Xpert 2+

- Stylish Fanless Design: PCH Heatsink

1 x PS/2 keyboard port (purple)

1 x PS/2 mouse port (green)

1 x DVI-D port

1 x RGB port

1 x HDMI port

1 x 5Gb/s USB Type C port

2 x USB 2.0/1.1 ports

2 x USB 3.0/2.0 ports (blue, Type A)

1 x LAN (RJ-45) port

3 x Audio jacks support 8-channel audio output*

* Use a chassis with HD audio module in the front panel to support an 8-channel

audio output.

1 x USB 3.0 / 2.0 connector supports additional 2 USB 3.0/ 2.0 ports (19-pin)

2 x USB 2.0 / 1.1 connectors support additional 4 USB 2.0/ 1.1 ports

6 x SATA 6.0 Gb/s connectors (gray)

2 x M.2 Socket 3 (for M Key, type 2242/2260/2280 devices)

1 x CPU fan connector (PWM mode only)

2 x Chassis Fan connectors (4-pin) for both 3-pin (DC mode) and 4-pin (PWM

mode) coolers control

1 x Front panel audio connector (AAFP)

1 x Speaker connector

1 x COM connector

1 x Chassis Intrusion header

1 x System panel connector

1 x Clear CMOS header

1 x S/PDIF Out header

1 x TPM connector

1 x LPT connector

1 x 24-pin EATX power connector

1 x 4-pin ATX 12V power connector

128Mb Flash ROM, UEFI AMI BIOS, PnP, DMI3.0, WfM2.0, SM BIOS 3.0,
ACPI 6.1, Multi-language BIOS, ASUS EZ Flash 3, CrashFree BIOS 3, F6

Qfan Control, F3 My Favorites, Last Modied log, F12 PrintScreen, and ASUS

DRAM SPD (Serial Presence Detect) memory information

(continued on the next page)

viii

PRIME B250M-A specications summary

Manageability WfM 2.0, DMI 3.0, WOL/WOR by PME, PXE

Drivers

Support DVD

OS support

Form factor mATX form factor: 9.6 in. x 8.1 in. (24.4 cm x 20.6 cm)

ASUS utilities

EZ Update

Anti-virus software (OEM version)

®

10 ( 64-bit)

Windows

®

8.1 (64-bit)*

Windows

®

7 (64-bit / 32-bit)*

Windows

* Windows® 8.1 64-bit and Windows® 7 32/64-bit are only supported when using 6th

Generation Intel® Processors.

Specications are subject to change without notice.

ix

Product introduction

Motherboard overview

• Unplug the power cord from the wall socket before touching any component.

• Before handling components, use a grounded wrist strap or touch a safely grounded

object or a metal object, such as the power supply case, to avoid damaging them due
to static electricity.

• Before you install or remove any component, ensure that the ATX power supply is

switched off or the power cord is detached from the power supply. Failure to do so
may cause severe damage to the motherboard, peripherals, or components.

• Unplug the power cord before installing or removing the motherboard. Failure to do so

can cause you physical injury and damage to motherboard components.

KBMS

ATX12V

DVI

VGA

USB3_C3

Place this

side towards

the rear of the

chassis

HDMI

USB3_56

LAN_USB78

CHA_FAN1

COM

Realtek
8111H

ALC
887

AAFP

SPDIF_OUT

2280 2260 2242

LANGuard

PCIEX1_1

PCIEX1_2

2280 2260 2242

LPT

16

AUDIO

19

18

17

16

321 42

20.6cm(8.1in)

CPU_FAN

LGA1151

M.2_1
PCIE SATA

X4 V X

PRIME B250M-A

PCIEX16

Super

BATTERY

I/O

M.2_2
PCIE SATA

X4 X V

TPM

12131415

11

1

CHA_FAN2

DIGI

+VRM

1

1

DDR4 DIMM_A1 (64bit, 288-pin module)

DDR4 DIMM_A2 (64bit,288-pin module)

DDR4 DIMM_B1 (64bit, 288-pin module)

DDR4 DIMM_B2 (64bit, 288-pin module)

EATXPWR

IRST

®

Intel
B250

SPEAKER

IRST

M.2_2(SOCKET3) M.2_1(SOCKET3)

USB3_12

USB1112USB910

CHASSIS

F_PANEL

SATA6G_5SATA6G_6 SATA6G_4

24.4cm(9.6in)

5

6

7

8

CLRTC

SATA6G_3 SATA6G_2 SATA6G_1

128Mb
BIOS

88 910

1-1

Scan the QR code to get the detailed pin denitions.

ASUS PRIME B250M-A

ATX power connectors (24-pin EATXPWR, 4-pin ATX12V)

Correctly orient the ATX power supply plugs into these connectors and push down

rmly until the connectors completely t.

•

For a fully congured system, we recommend that you use a power supply unit
(PSU) that complies with ATX 12 V Specication 2.0 (or later version) and provides

a minimum power of 350 W.

•

If you are uncertain about the minimum power supply requirement for your system,
refer to the Recommended Power Supply Wattage Calculator at http://support.
asus.com/PowerSupplyCalculator/PSCalculator.aspx?SLanguage=en-us for
details.

CPU and chassis fan connectors (4-pin CPU_FAN, 4-pin CHA_FAN 1/2)

Connect the fan cables to the fan connectors on the motherboard, ensuring that the
black wire of each cable matches the ground pin of the connector.

Do not forget to connect the fan cables to the fan connectors. Insufcient air ow inside

the system may damage the motherboard components. These are not jumpers! Do not
place jumper caps on the fan connectors! The CPU_FAN connector supports a CPU fan
of maximum 1A (12 W) fan power.

Intel® LGA1151 CPU socket

Install Intel

®

LGA1151 CPU into this surface mount LGA1151 socket, which is designed

for 7th / 6th Generation Intel® Core™ i7 / i5 / i3, Pentium®, and Celeron® processors.

For more details, refer to Central Processing Unit (CPU).

DDR4 DIMM slots

Install 2 GB, 4 GB, 8 GB, and 16 GB unbuffered non-ECC DDR4 DIMMs into these
DIMM sockets.

For more details, refer to System memory.

System panel connector (10-1 pin F_PANEL)

This connector supports several chassis-mounted functions.

Speaker connector (4-pin SPEAKER)

This 4-pin connector is for the chassis-mounted system warning speaker. The
speaker allows you to hear system beeps and warnings.

Chapter 1: Product introduction

1-2

PIN 1

Clear RTC RAM (2-pin CLRTC)

This header allows you to clear the CMOS RTC RAM
data of the system setup information such as date,
time, and system passwords.

CLRTC

To erase the RTC RAM:

+3V_BAT

1. Turn OFF the computer and unplug the power

GND

cord.

2. Use a metal object such as a screwdriver to
short the two pins.

3. Plug the power cord and turn ON the computer.

4. Hold down the <Del> key during the boot
process and enter BIOS setup to re-enter data.

If the steps above do not help, remove the onboard battery and short the two pins again
to clear the CMOS RTC RAM data. After clearing the CMOS, reinstall the battery.

Intel® B250 Serial ATA 6.0Gb/s connectors (7-pin SATA6G_1~6)

These connectors connect to Serial ATA 6.0 Gb/s hard disk drives via Serial ATA

6.0 Gb/s signal cables.

When using hot-plug and NCQ, set the SATA Mode Selection item in the BIOS to
[AHCI].

Chassis intrusion header (4-1 pin CHASSIS)

This header is for a chassis-mounted intrusion detection sensor or switch. Connect
one end of the chassis intrusion sensor or switch cable to this header. The chassis
intrusion sensor or switch sends a high-level signal to this header when a chassis
component is removed or replaced. The signal is then generated as a chassis
intrusion event.

By default, the pin labeled “Chassis Signal” and “Ground” are shorted with a
jumper cap. Remove the jumper caps only when you intend to use the chassis
intrusion detection feature.

USB 3.0 connector (20-1 pin USB3_12)

Connect a USB 3.0 module to this connector for additional USB 3.0 front or rear

panel ports. This connector complies with USB 3.0 specications and provides

faster data transfer speeds of up to 5 Gbps, faster charging time for USB-

chargeable devices, optimized power efciency, and backward compatibility with

USB 2.0.

USB 2.0 connectors (10-1 pin USB910, USB1112)

Connect the USB module cable to any of these connectors, then install the module
to a slot opening at the back of the system chassis. These USB connectors comply

with USB 2.0 specications and support up to 480Mbps connection speed.

1-3

ASUS PRIME B250M-A

TPM connector (14-1 pin TPM)

This connector supports a Trusted Platform Module (TPM) system, which can

securely store keys, digital certicates, passwords and data. A TPM system also

helps enhance network security, protects digital identities, and ensures platform
integrity.

LPT connector (26-1 pin LPT)

The LPT (Line Printing Terminal) connector supports devices such as a printer.

LPT standardizes as IEEE 1284, which is the parallel port interface on IBM PC-

compatible computers.

Serial port connector (10-1 pin COM)

This connector is for a serial (COM) port. Connect the serial port module cable to
this connector, then install the module to a slot opening at the back of the system
chassis.

Digital audio connector (4-1 pin SPDIF_OUT)

Connect the S/PDIF Out module cable to this
connector, then install the module to a slot opening at
the back of the system chassis.

M.2 socket 3

These sockets allow you to install an M.2 (NGFF) SSD

PIN 1

SPDIF_OUT

+5V

SPDIFOUT

GND

M.2(SOCKET3)

module.

These sockets support M Key and
2242/2260/2280 storage devices.

Front panel audio connector (10-1 pin AAFP)

This connector is for a chassis-mounted front panel audio I/O module that supports
either HD Audio or legacy AC`97 audio standard. Connect one end of the front
panel audio I/O module cable to this connector.

• We recommend that you connect a high-denition front panel audio module to this
connector to avail of the motherboard’s high-denition audio capability.

• If you want to connect a high-denition front panel audio module to this connector,

set the Front Panel Type item in the BIOS setup to [HD Audio]. If you want to
connect an AC’97 front panel audio module to this connector, set the item to
[AC97]. By default, this connector is set to [HD Audio].

PCI Express 3.0/2.0 x1 slots

This motherboard supports PCI Express 3.0/2.0 x1 network cards, SCSI cards, and

other cards that comply with the PCI Express specications

PCI Express 3.0/2.0 x16 slot

This motherboard has a PCI Express 3.0/2.0 x16 slot that supports PCI Express

3.0/2.0 x16 graphic cards complying with the PCI Express specications.

Chapter 1: Product introduction

1-4

IRQ assignments for this motherboard

A B C D

HD Audio shared – – –

XHCI Controller shared – – –

SATA Controller shared – – –
Realtek 8111H

LAN
PCIEx16 shared – – –
PCIEx1_1 shared – – –
PCIEx1_2 – shared – –
M.2_1 shared – – –

M.2_2 shared – – –

– – – shared

1-5

ASUS PRIME B250M-A

Rear panel connectors

1

2

4 53

12

11 9

10 8 7

6

1. PS/2 mouse port (green). This port is for a PS/2 mouse.

2. Video Graphics Adapter (VGA) port. This 15-pin port is for a VGA monitor or other

VGA-compatible devices.

Speed

3. LAN (RJ-45) port. This port allows Gigabit connection to a Local

Area Network (LAN) through a network hub.

LAN port LED indications

Activity Link

LED

LAN port

LED

Activity/Link LED Speed LED
Status Description Status Description

Off No link OFF 10Mbps connection
Orange Linked ORANGE 100Mbps connection
Orange (Blinking) Data activity GREEN 1Gbps connection
Orange (Blinking

then steady)

Ready to wake up
from S5 mode

_ _

4. Line In port (light blue). This port connects to the tape, CD, DVD player, or other

audio sources.

5. Line Out port (lime). This port connects to a headphone or a speaker. In the 4.1, 5.1

and 7.1-channel congurations, the function of this port becomes Front Speaker Out.

6. Microphone port (pink). This port connects to a microphone.

Refer to the audio conguration table for the function of the audio ports in 2.1, 4.1, 5.1, or

7.1-channel conguration.

Chapter 1: Product introduction

1-6

Audio 2.1, 4.1, 5.1, or 7.1-channel conguration

Port

Light Blue (Rear panel) Line In Rear Speaker Out Rear Speaker Out Rear Speaker Out
Lime (Rear panel) Line Out Front Speaker Out Front Speaker Out Front Speaker Out
Pink (Rear panel) Mic In Mic In Bass/Center Bass/Center

Lime (Front panel) - - - Side Speaker Out

To congure a 7.1-channel audio output:

Use a chassis with HD audio module in the front panel to support a 7.1-channel audio

Headset

2.1-channel

output.

4.1-channel 5.1-channel 7.1-channel

7. USB 2.0 ports. These 4-pin Universal Serial Bus (USB) ports are for USB 2.0/1.1

devices.

8. USB 3.0 ports. These 9-pin Universal Serial Bus (USB) ports are for USB 3.0/2.0

devices.

• USB 3.0 devices can only be used for data storage.

• We strongly recommend that you connect USB 3.0 devices to USB 3.0 ports for faster

and better performance from your USB 3.0 devices.

• Due to the design of the Intel

USB 2.0 and USB 3.0 ports are controlled by the xHCI controller. Some legacy USB

devices must update their rmware for better compatibility.

®

100 series chipset, all USB devices connected to the

9. HDMI port. This port is for a High-Denition Multimedia Interface (HDMI) connector,

and is HDCP compliant allowing playback of HD DVD, Blu-Ray, and other protected
content.

10. USB 5Gb/s Type C port. This 24-pin Universal Serial Bus (USB) port is for USB (Type

C) devices.

11. DVI-D port. This port is for any DVI-D compatible device.

DVI-D cannot be converted to output from RGB Signal to CRT and is not compatible with
DVI-I.

12. PS/2 keyboard port (purple). This port is for a PS/2 keyboard.

1-7

ASUS PRIME B250M-A

Central Processing Unit (CPU)

This motherboard comes with a surface mount LGA1151 socket
designed for 7th / 6th Generation Intel® Core™ i7 / i5 / i3, Pentium®, and

®

processors.

Celeron

Unplug all power cables before installing the CPU.

• Ensure that you install the correct CPU designed for the LGA1151 socket only. DO

NOT install a CPU designed for LGA1150, LGA1155 and LGA1156 sockets on the
LGA1151 socket.

• Upon purchase of the motherboard, ensure that the PnP cap is on the socket and

the socket contacts are not bent. Contact your retailer immediately if the PnP cap
is missing, or if you see any damage to the PnP cap/socket contacts/motherboard
components.

• Keep the cap after installing the motherboard. ASUS will process Return Merchandise
Authorization (RMA) requests only if the motherboard comes with the cap on the

LGA1151 socket.

• The product warranty does not cover damage to the socket contacts resulting from

incorrect CPU installation/removal, or misplacement/loss/incorrect removal of the PnP
cap.

Installing the CPU

1

A

3

Apply the Thermal Interface Material to the CPU heatsink and CPU before you install the
heatsink and fan if necessary.

Chapter 1: Product introduction

B

A

2

4

4

C

5

D

5

B

4

1-8

System memory

Overview

This motherboard comes with four Double Data Rate 4 (DDR4) Dual Inline Memory Module

(DIMM) sockets. The gure illustrates the location of the DDR4 DIMM sockets:

DIMM_A1
DIMM_A2

DIMM_B1
DIMM_B2

Channel Sockets

Channel A DIMM_A1 & DIMM_A2

Channel B DIMM_B1 & DIMM_B2

• You may install varying memory sizes in Channel A and Channel B. The system
maps the total size of the lower-sized channel for the dual-channel conguration. Any
excess memory from the higher-sized channel is then mapped for single-channel

operation.

• Always install the DIMMS with the same CAS Latency. For an optimum compatibility,

we recommend that you install memory modules of the same version or data code
(D/C) from the same vendor. Check with the vendor to get the correct memory
modules.

• According to Intel

®

CPU spec, DIMM voltage below 1.35V is recommended to protect

the CPU.

• Due to the memory address limitation on 32-bit Windows

®

OS, when you install 4GB
or more memory on the motherboard, the actual usable memory for the OS can be
about 3GB or less. For effective use of memory, we recommend that you do any of the
following:

- Use a maximum of 3 GB system memory if you are using a 32-bit Windows

- Install a 64-bit Windows

®

OS if you want to install 4GB or more on the

®

OS.

motherboard.

- For more details, refer to the Microsoft

®

support site at http://support.microsoft.

com/kb/929605/en-us.

• Visit the ASUS website at www.asus.com for the latest QVL.

1-9

ASUS PRIME B250M-A

Installing a DIMM

1 2

To remove a DIMM

A

B

A

A

B

Chapter 1: Product introduction

1-10

BIOS information

2

• Scan the QR code to view the BIOS update guide.

• Before using the ASUS CrashFree BIOS 3 utility, rename the

BIOS le in the removable device into B250MA.CAP.

BIOS setup program

Use the BIOS Setup program to update the BIOS or congure its parameters. The BIOS

screens include navigation keys and brief online help to guide you in using the BIOS Setup
program.

Entering BIOS Setup at startup

To enter BIOS Setup at startup:

Press <Delete> or <F2> during the Power-On Self Test (POST). If you do not press <Delete>
or <F2>, POST continues with its routines.

Entering BIOS Setup after POST

To enter BIOS Setup after POST:

• Press <Ctrl>+<Alt>+<Del> simultaneously.

• Press the reset button on the system chassis.

• Press the power button to turn the system off then back on. Do this option only if you
failed to enter BIOS Setup using the rst two options.

Using the power button, reset button, or the <Ctrl>+<Alt>+<Del> keys to force reset from a
running operating system can cause damage to your data or system. We recommend you
always shut down the system properly from the operating system.

• The BIOS setup screens shown in this section are for reference purposes only, and

may not exactly match what you see on your screen.

• Visit the ASUS website at www.asus.com to download the latest BIOS le for this

motherboard.

• If the system becomes unstable after changing any BIOS setting, load the default

settings to ensure system compatibility and stability. Select the Load Optimized
Defaults item under the Exit menu or press hotkey F5.

• If the system fails to boot after changing any BIOS setting, try to clear the CMOS and

reset the motherboard to the default value. See section Motherboard overview for
information on how to erase the RTC RAM.

BIOS menu screen

The BIOS setup program can be used under two modes: EZ Mode and Advanced Mode.
Press <F7> to change between the two modes.

2-1

ASUS PRIME B250M-A

EZ Mode

By default, the EZ Mode screen appears when you enter the BIOS setup program. The EZ
Mode provides you an overview of the basic system information, and allows you to select the

display language, system performance mode, fan prole and boot device priority. To access

the Advanced Mode, click Advanced Mode(F7) or press <F7>.

The default screen for entering the BIOS setup program can be changed.

Displays the system properties of

Displays the CPU/motherboard
temperature, CPU voltage output,
CPU/chassis fan speed, and SATA
information

Selects the display
language of the BIOS
setup program

the selected mode. Click <Enter> to

switch EZ System Tuning modes

Displays the CPU Fan’s speed

Click the button to manually

The boot device options vary depending on the devices you installed to the system.

Chapter 2: BIOS information

tune the fans

Loads optimized

default settings

Shows the

bootable

devices

Saves the changes

and resets the

system

Displays the

Advanced mode

menus

Search on FAQs

Selects the boot

device priority

2-2

Advanced Mode

The Advanced Mode provides advanced options for experienced end-users to congure the
BIOS settings. The gure below shows an example of the Advanced Mode. Refer to the
following sections for the detailed congurations.

To access the EZ Mode, click EzMode(F7) or press <F7>.

Menu bar

Menu items

MyFavorite

Language

Q-Fan control

Hot Keys

General helpSub-menu items

Conguration elds

Popup window

Scroll bar

Last modied

settings

Goes back to EZ

Displays the CPU temperature, CPU

and memory voltage output

Search on FAQs

Mode

2-3

ASUS PRIME B250M-A

Search on FAQ

Move your mouse over this button to show a QR code. Scan this QR code with your mobile
device to connect to the ASUS BIOS FAQ web page. You can also scan the QR code below.

Exit menu

The Exit menu items allow you to load the optimal default values for the BIOS items, and
save or discard your changes to the BIOS items.

Load Optimized Defaults

This option allows you to load the default values for each of the parameters on the Setup

menus. When you select this option or if you press <F5>, a conrmation window appears.

Select OK to load the default values.

Save Changes & Reset

Once you are nished making your selections, choose this option from the Exit menu to

ensure the values you selected are saved. When you select this option or if you press <F10>,

a conrmation window appears. Select OK to save changes and exit.

Discard Changes and Exit

This option allows you to exit the Setup program without saving your changes. When you

select this option or if you press <Esc>, a conrmation window appears. Select OK to discard

changes and exit.

Launch EFI Shell from USB drives

This option allows you to attempt to launch the EFI Shell application (shellx64.e) from one of

the available USB devices.

Chapter 2: BIOS information

2-4

Appendix

Appendix

Notices

Federal Communications Commission Statement

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two
conditions:

• This device may not cause harmful interference.

• This device must accept any interference received including interference that may cause

undesired operation.

This equipment has been tested and found to comply with the limits for a Class B digital
device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a residential installation. This
equipment generates, uses and can radiate radio frequency energy and, if not installed
and used in accordance with manufacturer’s instructions, may cause harmful interference
to radio communications. However, there is no guarantee that interference will not occur
in a particular installation. If this equipment does cause harmful interference to radio or
television reception, which can be determined by turning the equipment off and on, the user
is encouraged to try to correct the interference by one or more of the following measures:

• Reorient or relocate the receiving antenna.

• Increase the separation between the equipment and receiver.

• Connect the equipment to an outlet on a circuit different from that to which the receiver

is connected.

• Consult the dealer or an experienced radio/TV technician for help.

A-1

The use of shielded cables for connection of the monitor to the graphics card is required

to assure compliance with FCC regulations. Changes or modications to this unit not

expressly approved by the party responsible for compliance could void the user’s authority
to operate this equipment.

ASUS PRIME B250M-A

IC: Canadian Compliance Statement

Complies with the Canadian ICES-003 Class B specications. This device complies with RSS

210 of Industry Canada. This Class B device meets all the requirements of the Canadian
interference-causing equipment regulations.

This device complies with Industry Canada license exempt RSS standard(s). Operation is
subject to the following two conditions: (1) this device may not cause interference, and (2)
this device must accept any interference, including interference that may cause undesired
operation of the device.

Cut appareil numérique de la Classe B est conforme à la norme NMB-003 du Canada.
Cet appareil numérique de la Classe B respecte toutes les exigences du Règlement sur le
matériel brouilleur du Canada.

Cet appareil est conforme aux normes CNR exemptes de licence d’Industrie Canada. Le
fonctionnement est soumis aux deux conditions suivantes :

(1) cet appareil ne doit pas provoquer d’interférences et

(2) cet appareil doit accepter toute interférence, y compris celles susceptibles de provoquer
un fonctionnement non souhaité de l’appareil.

Canadian Department of Communications Statement

This digital apparatus does not exceed the Class B limits for radio noise emissions from
digital apparatus set out in the Radio Interference Regulations of the Canadian Department
of Communications.

This class B digital apparatus complies with Canadian ICES-003.

VCCI: Japan Compliance Statement

Class B ITE

KC: Korea Warning Statement

Appendix

A-2

REACH

Complying with the REACH (Registration, Evaluation, Authorisation, and Restriction of
Chemicals) regulatory framework, we published the chemical substances in our products at
ASUS REACH website at http://csr.asus.com/english/REACH.htm.

DO NOT throw the motherboard in municipal waste. This product has been designed to
enable proper reuse of parts and recycling. This symbol of the crossed out wheeled bin
indicates that the product (electrical and electronic equipment) should not be placed in
municipal waste. Check local regulations for disposal of electronic products.

DO NOT throw the mercury-containing button cell battery in municipal waste. This symbol
of the crossed out wheeled bin indicates that the battery should not be placed in municipal
waste.

ASUS Recycling/Takeback Services

ASUS recycling and takeback programs come from our commitment to the highest standards
for protecting our environment. We believe in providing solutions for you to be able to
responsibly recycle our products, batteries, other components as well as the packaging
materials. Please go to http://csr.asus.com/english/Takeback.htm for detailed recycling
information in different regions.

Regional notice for California

WARNING! This product may contain chemicals known to the State of California to cause

cancer, birth defects or other reproductive harm. Wash hands after handling.

Google™ License Terms

Copyright© 2016 Google Inc. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this le

except in compliance with the License. You may obtain a copy of the License at:

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the
License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
ANY KIND, either express or implied.

See the License for the specic language governing permissions and limitations under the

License.

A-3

ASUS PRIME B250M-A

English ASUSTeK Computer Inc. hereby declares that this device is in
compliance with the essential requirements and other relevant provisions of
related Directives. Full text of EU declaration of conformity is available at:
www.asus.com/support

Français AsusTek Computer Inc. déclare par la présente que cet appareil est
conforme aux critères essentiels et autres clauses pertinentes des directives
concernées. La déclaration de conformité de l’UE peut être téléchargée à
partir du site Internet suivant : www.asus.com/support.

Deutsch ASUSTeK Computer Inc. erklärt hiermit, dass dieses Gerät mit
den wesentlichen Anforderungen und anderen relevanten Bestimmungen
der zugehörigen Richtlinien übereinstimmt. Der gesamte Text der EU­Konformitätserklärung ist verfügbar unter: www.asus.com/support

Italiano ASUSTeK Computer Inc. con la presente dichiara che questo
dispositivo è conforme ai requisiti essenziali e alle altre disposizioni pertinenti
con le direttive correlate. Il testo completo della dichiarazione di conformità
UE è disponibile all’indirizzo: www.asus.com/support

Русский Компания ASUS заявляет, что это устройство соответствует
основным требованиям и другим соответствующим условиям
соответствующих директив. Подробную информацию, пожалуйста,
смотрите на www.asus.com/support

Български С настоящото ASUSTeK Computer Inc. декларира, че това
устройство е в съответствие със съществените изисквания и другите
приложими постановления на свързаните директиви. Пълният текст на
декларацията за съответствие на ЕС е достъпна на адрес:

www.asus.com/support
Hrvatski ASUSTeK Computer Inc. ovim izjavljuje da je ovaj uređaj sukladan

s bitnim zahtjevima i ostalim odgovarajućim odredbama vezanih direktiva.
Cijeli tekst EU izjave o sukladnosti dostupan je na: www.asus.com/support

Čeština Společnost ASUSTeK Computer Inc. tímto prohlašuje, že toto
zařízení splňuje základní požadavky a další příslušná ustanovení souvisejících
směrnic. Plné znění prohlášení o shodě EU je k dispozici na adrese:
www.asus.com/support

Dansk ASUSTeK Computer Inc. erklærer hermed, at denne enhed er i
overensstemmelse med hovedkravene og andre relevante bestemmelser i de
relaterede direktiver. Hele EU-overensstemmelseserklæringen kan findes på:
www.asus.com/support

Nederlands ASUSTeK Computer Inc. verklaart hierbij dat dit apparaat
voldoet aan de essentiële vereisten en andere relevante bepalingen van
de verwante richtlijnen. De volledige tekst van de EU-verklaring van
conformiteit is beschikbaar op: www.asus.com/support

Eesti Käesolevaga kinnitab ASUSTeK Computer Inc, et see seade vastab
asjakohaste direktiivide oluliste nõuetele ja teistele asjassepuutuvatele
sätetele. EL vastavusdeklaratsiooni täielik tekst on saadaval järgmisel
aadressil: www.asus.com/support

Suomi ASUSTeK Computer Inc. ilmoittaa täten, että tämä laite on
asiaankuuluvien direktiivien olennaisten vaatimusten ja muiden tätä
koskevien säädösten mukainen. EU-yhdenmukaisuusilmoituksen koko teksti
on luettavissa osoitteessa: www.asus.com/support

Ελληνικά Με το παρόν, η AsusTek Computer Inc. δηλώνει ότι αυτή η
συσκευή συμμορφώνεται με τις θεμελιώδεις απαιτήσεις και άλλες σχετικές
διατάξεις των Οδηγιών της ΕΕ. Το πλήρες κείμενο της δήλωσης συμβατότητας
είναι διαθέσιμο στη διεύθυνση: www.asus.com/support

Magyar Az ASUSTeK Computer Inc. ezennel kijelenti, hogy ez az eszköz
megfelel a kapcsolódó Irányelvek lényeges követelményeinek és egyéb
vonatkozó rendelkezéseinek. Az EU megfelelőségi nyilatkozat teljes szövege
innen letölthető: www.asus.com/support

Latviski ASUSTeK Computer Inc. ar šo paziņo, ka šī ierīce atbilst saistīto
Direktīvu būtiskajām prasībām un citiem citiem saistošajiem nosacījumiem.
Pilns ES atbilstības paziņojuma teksts pieejams šeit: www.asus.com/support

Lietuvių „ASUSTeK Computer Inc.“ šiuo tvirtina, kad šis įrenginys atitinka
pagrindinius reikalavimus ir kitas svarbias susijusių direktyvų nuostatas. Visą
ES atitikties deklaracijos tekstą galima rasti: www.asus.com/support

Norsk ASUSTeK Computer Inc. erklærer herved at denne enheten er i
samsvar med hovedsaklige krav og andre relevante forskrifter i relaterte
direktiver. Fullstendig tekst for EU-samsvarserklæringen finnes på:
www.asus.com/support

Polski Firma ASUSTeK Computer Inc. niniejszym oświadcza, że
urządzenie to jest zgodne z zasadniczymi wymogami i innymi właściwymi
postanowieniami powiązanych dyrektyw. Pełny tekst deklaracji zgodności UE
jest dostępny pod adresem: www.asus.com/support

Português A ASUSTeK Computer Inc. declara que este dispositivo está em
conformidade com os requisitos essenciais e outras disposições relevantes
das Diretivas relacionadas. Texto integral da declaração da UE disponível em:
www.asus.com/support

Română ASUSTeK Computer Inc. declară că acest dispozitiv se conformează
cerinţelor esenţiale şi altor prevederi relevante ale directivelor conexe. Textul
complet al declaraţiei de conformitate a Uniunii Europene se găseşte la:
www.asus.com/support

Srpski ASUSTeK Computer Inc. ovim izjavljuje da je ovaj uređaj u saglasnosti
sa osnovnim zahtevima i drugim relevantnim odredbama povezanih
Direktiva. Pun tekst EU deklaracije o usaglašenosti je dostupan da adresi:
www.asus.com/support

Slovensky Spoločnosť ASUSTeK Computer Inc. týmto vyhlasuje, že toto
zariadenie vyhovuje základným požiadavkám a ostatým príslušným
ustanoveniam príslušných smerníc. Celý text vyhlásenia o zhode pre štáty EÚ
je dostupný na adrese: www.asus.com/support

Slovenščina ASUSTeK Computer Inc. izjavlja, da je ta naprava skladna z
bistvenimi zahtevami in drugimi ustreznimi določbami povezanih direktiv.
Celotno besedilo EU-izjave o skladnosti je na voljo na spletnem mestu:
www.asus.com/support

Español Por la presente, ASUSTeK Computer Inc. declara que este dispositivo
cumple los requisitos básicos y otras disposiciones pertinentes de las
directivas relacionadas. El texto completo de la declaración de la UE de
conformidad está disponible en: www.asus.com/support

Svenska ASUSTeK Computer Inc. förklarar härmed att denna
enhet överensstämmer med de grundläggande kraven och andra
relevanta föreskrifter i relaterade direktiv. Fulltext av EU-försäkran om
överensstämmelse finns på: www.asus.com/support

Українська ASUSTeK Computer Inc. заявляє, що цей пристрій відповідає
основним вимогам та іншим відповідним положенням відповідних
Директив. Повний текст декларації відповідності стандартам ЄС
доступний на: www.asus.com/support

Türkçe AsusTek Computer Inc., bu aygıtın temel gereksinimlerle ve ilişkili
Yönergelerin diğer ilgili koşullarıyla uyumlu olduğunu beyan eder. AB
uygunluk bildiriminin tam metni şu adreste bulunabilir:
www.asus.com/support

Bosanski ASUSTeK Computer Inc. ovim izjavljuje da je ovaj uređaj usklađen
sa bitnim zahtjevima i ostalim odgovarajućim odredbama vezanih direktiva.
Cijeli tekst EU izjave o usklađenosti dostupan je na: www.asus.com/support

Appendix

A-4

ASUS contact information

ASUSTeK COMPUTER INC.

Address 4F, No. 150, Li-Te Road, Peitou, Taipei 112, Taiwan
Telephone [phone]
Fax [phone]
Web site www.asus.com

Technical Support

Telephone [phone]
Fax [phone], ext. 9101#
Online support http://qr.asus.com/techserv

ASUS COMPUTER INTERNATIONAL (America)

Address 800 Corporate Way, Fremont, CA 94539, USA
Telephone [phone]
Fax [phone]
Web site http://www.asus.com/us/

Technical Support

Support fax [phone]
Telephone [phone]
Online support http://qr.asus.com/techserv

ASUS COMPUTER GmbH (Germany and Austria)

Address Harkort Str. 21-23, 40880 Ratingen, Germany
Fax [phone]
Web site http://www.asus.com/de
Online contact http://eu-rma.asus.com/sales

Technical Support

Telephone [phone]
Support Fax [phone]
Online support http://qr.asus.com/techserv

A-5

ASUS PRIME B250M-A

DECLARATION OF CONFORMITY

Date : Oct. 10, 2016

Per FCC Part 2 Section 2. 1077(a)

Responsible Party Name: Asus Computer International

Address: 800 Corporate Way, Fremont

, CA 94539.

Phone/Fax No: [phone]/[phone]

hereby declares that the product

Product Name : Motherboard

Model Number : PRIME B250M-A

Conforms to the following specifications:

FCC Part 15, Subpart B, Unintentional Radiators

Supplementary Information:

This device complies with part 15 of the FCC Rules. Operation is subject to the

following two conditions: (1) This device may not cause harmful interference,
and (2) this device must accept any interference received, including interference

that may cause undesired operation.

Representative Person’s Name : Steve Chang / President

Signature :

Appendix

Ver. 140331

A-6