RCA ATC010 Schematic

VERTICAL

TO
E8

RED BIAS

<21-B>

TO
E7

GRN BIAS

E5003

E5007

TP50

RED OUTPUT

TP24

194V

TECHNICAL TRAINING

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ATC010

Technical Training Manual

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FOREWORD

This manual provides the service technician circuit information and troubleshooting
steps to be used while repairing the ATC010 chassis. It is intended as a training tool
and is to be used in conjunction with the ESI service information. As wi th other
training manuals, circuit description is represented with partial schematics and not
all components in a circuit are listed.

SAFETY INFORMATION CAUTION

Safety information is contained in the appropriate Service Data. All product safety
requirements must be complied with prior to returning the instrument to the
consumer. Servicers who defeat safety features or fail to perform safety checks may
be liable for any resulting damages and may expose themselves and others to
possible injury.

All integrated circuits, all surface mounted devices, and
many other semiconductors are electrostatically sensitive
and therefore require special handling techniques.

First Edition - First Printing
Copyright 2005 TTE Technology, Inc.
Trademark(s)
RCA and associated marks are trademarks of
THOMSON S.A. used under license to TTE
CORPORATION.

Printe d in U.S. A.

®

Registered Marca(s) Registrada(s)

Prepared by
Thomson, Inc for TTE Technology, Inc.
Technical Training Department, INH905
PO Box 1976
Indianapolis, Indiana 46206 U.S.A.

Contents

FOREWORD ............................................................. 3

SAFETY INFO RMATION CAUTION ......................... 3

Overview .................................................................. 5

Standby Power Supply............................................ 6

Run Power Supply................................................. 10

System Control (All-IN-ONE Processor).............. 13

Horizontal Deflection............................................. 15

V ertical Deflection ................................................. 17

Shutdown............................................................... 18

ADM1 Module (ATSC Tuner) ................................. 20

Standby Power Supply Troubleshooting ............. 22

Run Power Supply Troubleshooting.................... 23

System Control Troubleshooting.........................25

ADM1 T roubleshooting ......................................... 26

Shutdown Troubleshooting.................................. 27

Overview

The ATC010 Training Manual covers the key circuits found i n the new ATC010
chassis. These circuits include:

· Standby Power Supply

· Run Power Supply

· System Control (ALL-IN-ONE P rocessor)

· Horizontal Deflection

· Vertical Deflection

· Shutdown Circuits

· ADM1 Module

This new chassis combines previous NTSC technology with new High Definiti on
technology. This combination allows HD programming to be received and displayed
on a standard NTSC (4:3) set. It also combines all processing and switching into a
single IC package the ALL-IN-ONE Processor.

The ALL-IN-ONE Processor is just that a single IC that handles all video switching,
audio switching, deflection processi ng, video processing, audio processing, a nd
system control functions. The only processing not performed by this IC is the ATSC
signal tuning and decoding.

P900 REAR

AV OUTPUT

P902

REAR AV IN

P901/P903

REAR AV IN

S-SHS IN

P960/P905

SIDE AV IN

SIDE SVHS IN

P904 REAR
Y Pb Pr IN

24.576MHZ

P203

from

ADM1

Y Pr Pb

36 A-OUTSL
37 A-OUTSR
48 SVO

53 AUDIO INL
54 AUDIO INR
55 CVBS2/Y2

49 AUDIO INL
50 AUDIO INR
51 CVBS4/Y4
52 C4

56 AUDIO INL
57 AUDIO INR
58 CVBS3/Y3
59 C2/C3

78 R/PrIN3
79 G/YIN3
80 B/PbIN3

PLL

10 XTAL IN

11 XTAL OUT

TUNER

NTSC

70 R/Pr
72 G/Y
71 B/Pb

AV Port

AGC

31
AGC OUT

VIF & SIF

Decoder

YUV Processor

Micro

CC V-Chip

IO Port

IR

LED

VIF / SIF

Color

P
O

W

E
R

SAW

NVM

Jungle

DSP

Stereo

IC200

RGB

RGB OUT
85,86,87

ROTATION

113

SVM 65

VDRA 23
VDRB 22

E-W 21

HD 67

FeedBack 16

AUDIO

PRE
OUT

RGB

PWM

RGB Amp

Rot Amp

VM

V-out

Pin out
H-drive
HOT

Feedback

AUDIO AMP

to YOKE

FBT

L

R

Key buttons

ATC010 System Block

Page 5

ATSC decoding and receiving is performed on the ADM1 modul e. This module
receives and processes high definition signals and converts them to a format used
by the chassis.

Troubleshooting procedures covering key ci rcuits is also provided in this manual.
These key circuits include:

· Standby Power Supply

· Run Power Supply

· System Control

·ADM1
Each troubleshooting procedure is a step by step circuit verification process.
Knowledge of the circuit is critical to following these procedures. It is recommended
the servicing technician become familiar with the circuits before using the procedures
to troubleshoot the ATC010 chassis.

Standby Power Supply

The standby power supply in the ATC010 is operational when ever AC power is
applied to the chassis. The supply operates with an AC voltage level between 108V
to 132V. It is a switch m ode power supply that generates the +5V STB voltage from
the 120VAC input. This voltage is further regulated to a +3.3VSTBY that is used by
System Control and other circuits that require standby voltage.

The heart of the standby suppl y is IC860 switch mode controller IC. IC860 uses
voltage mode control and Pulse Width Modulation (PWM) to drive the power
transformer T860. Voltage mode control is at start up when the vol tage on pin 1
passes the start level of IC860. The PWM frequency is determined by the time it
takes for the transformer to demagnetize and an external RC network on pin 3.

Start-up

Startup of the supply occurs when AC is applied to bri dge rectifier di odes D861,
D862, D863, and D864. The AC is converted to Raw B+ (approximately +150VDC
DC) by the bridge rectifier and C860 filter. Raw B+ is the source voltage for switching
transformer T860 supplied by current limiting resistor RT860.

The switching transformer (T860) allows connection of the Raw B+ to the switch
mode controller IC through its primary winding between pin 5 and 3. Pin 3 of T860
is connected to pin 8 of IC860. IC860-8 is the Drain supply and startup for the IC.
As the Raw B+ increases on pin 8 of IC860, the IC starts to conduct through pin 6
and the current source resistor R862. As the vol tage at pin 6 of IC860 increases,
over-current is detected shutting down the IC. This releases the stored energy in the
primary of T860 to the secondary windings.

Page 6

The induced voltage between secondary winding pins 1 and 2 of T860 is rectified by
D865 and filtered by C864. This voltage is used as VCC for IC860-1 and IC804-4
feedback regulation circuit. IC860 starts switching when the voltage on pin 1 passes
the VCC start level. Once this voltage is high enough to operate the IC, voltage from
pin 8 (Raw B+) is no longer used to power the IC.

IC860 operates in discontinuous conduction mode. This means that as long as there
is a pulse on the secondary of T860, the oscillat or (IC860) will not start a new p rimary
pulse. Pin 5 of IC860 m onitors the current in T860 and suppresses start of the next
cycle while there a re s t ill s e c ondary pulses from T860.

Regulation

There are two regulation circuits in the ACT010 standby power supply. D866 and
the winding from T860 pins 1 and 2 make up the secondary or fail safe regulation and
IC804 provides secondary monitoring regulation as the primary regulation. Both are
sent to IC860 pin 4 (REG input).

P802

P801

F800

C893

R849

C862
R864

C801
R801

R863

C863

T801

C861

D866

18V

IC860

1
2
3
4

4
3

R865

C864

C860
R860

D860

8

C890

7

R862

6
5

D865

1

IC804

2

RT860

R861

D861
D862
D863
D864

T860

5

3

2

1

AC-RUN

AC-RUN

R890

D868

6

L861

+5VSTB
C866
C868

10

R869

R868

R867

Q860

D869

3.3V

R891
C895

+5VSTB

R081

D080

3.9V

Q080

C083

+3.3VSTB

C082

C081

Page 7

The primary regulation is feed back from the secondary +5VSTB source through
opto-coupler IC804. As the +5VSTB increases, current through IC804 (LE D side)
pin 1 and 2 increases. This increase is detected by the photo transistor on pins 3 and
4 causing IC804 pins 3 and 4 to conduct more. This increase in current is sent to pin
4 of IC860 causing i t to limit on time. The output voltage, in this case +5V, is
determined by Q860, D869, and voltage divider circuit R868 and R867.

Over Voltage Pr otection

The over voltage protection level is determined by D866. If the primary feed back
fails to control regulation D866 will prevent the po we r supply from reaching unsafe
levels. As the voltage increases in the secondary the voltage on the cathode of D866
also increases. Once this voltage reached the break over point of D866 (18V) D866
conducts and pin 4 of IC860 voltage increases shutting down IC860.

Over Current Protection

The current source resistor R861 determines the amount of current the power supply
can generate. As the current increases in R861, the voltage at pin 5 of IC860 starts
to increase. Once this voltage reaches the internal threshold of the IC, IC860 goes
into over current protection.

Other protections for IC860 incl ude Over Temperature and Short Circuit Winding
Protection. These protection circuits are internal of IC860 and can not be measured.
However; they both have unique circumstance that a servicer can use to determine
which shutdown it is. First is thermo shutdown, as the name implies, thermo
shutd o wn is temperatu r e r e la t ed . I f I C 8 60 g e ts t o o h ot , it will shutdo wn. With this
type of shutdown the power supply will run until the shutdown temperature is m et and
then the power supply will shutdown. Cooling down the IC will resume normal
operation of the power supply. Second, the Short Circuit Winding requires a power
on res et to c lea r. On ce activ at ed , t he s ho rt cir cu it w in din g shu td ow n will not allow
the power supply to operate until the short is removed. This results in a com pletely
dead power supply (no pulsing or oscillations).

The only supply voltage generated by the standby supply is +5VSTB. This voltage
is used to run all standby circuits and is further regulated to +3.3V that is used by
system control functions. Relay K802, run supply switch, also uses the +5VSTB

Q080

+5VSTB

R081

D080

3.9V

C083

+3.3VSTB

C082

C081

Page 8

P801

P802

AC-STBY

F800

T801

T802

D801

RT801

X800

P803

K801

P801

+5VSTB

ON/OFF

IC200
Pin99

SysCon

P802

R849

C862
R864

C801
R801

AC-STBY

F800

C801
R801

C893

R863

C863

T801

C861

D866

18V

K802

D867

IC860

1
2
3
4

4
3

Q861

R865

C864

C860
R860

D860

8

C890

7

R862

6
5

D865

1

IC804

2

RT860

R861

D861
D862
D863
D864

T860

5

3

2

1

AC-RUN

AC-RUN

R890

Run Supply

Start-UP

to R810

Run Supply

D868

6

10

R868

R867

Q880

Raw B+
to RT802

L861

R869

+12V RUN

D880

RELAY

IC200

Pin 112

SysCon

+5VSTB
C866
C868

Q860

D869

3.3V

R891
C895

Page 9