Philco PFS2908 Schematic

FILE NO.

SERVICE MANUAL Colour Television

Model No. PFS2908

(Argentina)

Service Ref. No. PFS2908-00

Specifications

Power Source . . . . . . . . AC220V, 50Hz / 60Hz

Receiving System . . . . . PAL (M/M, N/N), NTSC (M/M)

Channel Coverage

Antenna mode VHF: CH02-CH13, UHF: CH14-CH69
CATV mode VHF band: CH01-CH13, Mid band: CH14-CH22
Super band: CH23-CH36, Hyper band: CH37-CH64
Ultra band: CH65-CH94 and CH100-CH125
Low mid band: CH95-CH99

Video IF . . . . . . . . . . . . . 45.75MHz

Aerial Input Impedance 75Ω
Input Terminals

AV1 (Video): Composite Video Input (Phone Jack) x 1
S-Video Input (Separated Y/C) DIN 4-pin Jack x 1
AV1 (Audio):L/R Stereo Input (Phone Jack) x 1 set
AV2 (Video):Composite Video Input (Phone Jack) x 1
AV2 (Audio):L/R Stereo Input (Phone Jack) x 1 set
DVD (Video): Component Y, C
DVD (Audio): L/R Stereo Input (Phone Jack) x 1 set
Output Terminals
Video Monitor Output: Phono jack x 1
Audio Monitor Output: L/R Stereo Output (Phone Jack) x 1 set
Headphone Jack: Mini stereo jack x 1

Sound Output (RMS) . . . 5W + 5W

Speaker . . . . . . . . . . . . . . 6cm x 12cm x 2 pcs.

Dimensions . . . . . . . . . . . 750(W) x 590(H) x 416.5(D) mm

Weight . . . . . . . . . . . . . . . approx. 36.5 Kg

Specifications subject to change without notice.

B, CR Input (Phone Jack) x 1 set

Product Code: 113020208

Original Version

Chassis Series: LB6-A

Give complete “SERVICE REF. NO.” for
parts order or servicing. It is shown on the
rating plate at the cabinet back of the unit.

This T.V. receiver will not work properly in
foreign countries where the television trans­mission system and power source differ from
the design specifications. Refer to the speci­fication table.

BG4J

Contents

Safety Notice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Chassis Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

IC Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

Service Adjustments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18

Cabinet Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Chassis Electrical Parts List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-27

Safety Notice

SAFETY PRECAUTIONS

1: An isolation transformer should be connected in the

power line between the receiver and the AC line
when a service is performed on the primary of the
converter transformer of the set.

2: Comply with all caution and safety-related notes

provided on the cabinet back, inside the cabinet, on
the chassis or the picture tube.

3: When replacing a chassis in the cabinet, always

be certain that all the protective devices are
installed properly, such as, control knobs, adjust­ment covers or shields, barriers, isolation resistor­capacitor networks etc.. Before returning any
television to the customer, the service techni­cian must be sure that it is completely safe
to operate without danger of electrical shock.

X-RADIATION PRECAUTION

The primary source of X-RADIATION in television receiver is the picture tube. The picture tube is specially con­structed to limit X-RADIATION emissions. For continued X-RADIATION protection, the replacement tube must
be the same type as the original including suffix letter. Excessive high voltage may produce potentially hazard­ous X - RADIATION. To avoid such hazards, the high voltage must be maintained within specified limit. Refer
to this service manual, high voltage adjustment for specific high voltage limit. If high voltage exceeds specified
limits, take necessary corrective action. Carefully follow the instructions for + B1 volt power supply adjustment,
and high voltage check to maintain the high voltage within the specified limits.

PRODUCT SAFETY NOTICE

Product safety should be considered when a component replacement is made in any area of a receiver.
Components indicated by mark in the parts list and the schematic diagram designate components in which

safety can be of special significance. It is particularly recommended that only parts designated on the parts list
in this manual be used for component replacement designated by mark . No deviations from resistance

wattage or voltage ratings may be made for replacement items designated by mark .

-2-

Chassis Block Diagrams

P10/21

Antenna

CRT DRIVE

TRC

B

/

G/R

W

S

Y

E

K

V

0

0

2+

B

/

G/

R

HV/Fo/Sc

R/C PRE-AMP

TUNER BUS H-OUT DY-H

IF

DY-V

(LV76113) HORIZ-DRIVE HORIZ-OUT

SAW

TU

O W

Ere

tl

i

f

FBP

E

SU

L

P

T

B

FNI

SUSOC

AV2/DVD/S-VIDEO C VIDEO

V-

/E

-14187AL

(

+VOEDIV

T

UO ROTINOM

S-VIDEO Y/AV1-V

TU

O-

TR

E

VOEDI

V

PM33

52M

JN

AV1/AV2/DVD AUDIO IN AUDIO BUS

MONITOR OUT AUDIO

AUDIO L/R

SPEAKER(L)

SIF OUT

LR

/L

)307

27

AL

(

R)

E

-50

224AL

(R/

L

R

/L

DVD

/2VA

/

1

V

A

PFB2504CT

TUPN

I

O

IDUA

TU

O-

OIDU

ATUP

TUO

O

ID

UA

)NEK

N

A

S

(V0

22C

A

SPEAKER(R)

POWER

LA7846NZ

)

+28V

+32V

+5V

+8V

-16V

+

8

V

+5VRC

+

5VRC

+28V

+140V

10V

10V

+

5V

+16V

+8V

+8V

SIGNAL PROCESSING CIRCUIT

-3-

IC Block Diagrams

FUNCTIONAL BLOCK DIAGRAM

IC601 POWER SUPPLY IC (STRW6754)

-4-

IC Block Diagrams

IC201 < IF/Video/Chroma/Def./CPU > LA76113

-5-

IC Block Diagrams

IC501<Vertical.Output> LA78141

IC001<AUDIO AMP> LA42205

-6-

IC Block Diagrams

10 11 12

Slave Address = 80h ( 1000 000* ) :Pin8=OPEN/GND

Slave Address = 84h ( 1000 010* ) :Pin8=H

Vcc 5V

+

98

65 7

4

21 3

21

2324

22

15

14 13

161719

20

18

MATR IX

MODE

OUT

REGU LATOR

+ ++

+

+

+

+

+

+

4.5M

BPF

LPF

SIF DEMOD

SAP BPF

SAP

DEMOD

L-R

DEMOD

ST/SAP

SW

LPF

-6dB

PILOT

CANCELLER

STERE O

PLL

PILOT

DET

PILOT

LEV EL DET

IIC

DECODE

SYSTE M

CONTROL

Offset

Cancell

dbx processor

SAP

DET

4u7

4u7

22u

4u7

OUT(L) OUT(R)

MODE

Monitor

2u2

1u

1u

0.1?

1u

4k7

MUTE

L+R

L-R/SAP

ST

SAP

Address

Control

GND

MU TE

Wide RMS DET

Spectral DET

Spectral In

Offset Cancel

0.1u

0.1u

4u7

1u to

0.33u

SIF SIGNAL

from Tuner

Address

Control

IIC

DATA

IIC

CLOC K

2u2

22u

Spectral RMS

DET

100u

0.1u

47u

+

10u

+

10u

33n

33n

+

1u

+

560k

LPF

IC3401　LA72703

-7-

IC Block Diagrams

IC1001 TC4052BF

IC1002 NJM2533M

-8-

Service Adjustments

General

This set has an On-screen Service Menu system included in the CPU that allows remote operation for most of the
service adjustments.

IC802 (EEPROM) Replacement

When IC802 (EEPROM) is replaced, IC201 (CPU) will automatically write the initial reference data into IC802 for basic TV operation.
However, the bus data should be checked and some bus data should be set up before attempting the service adjustments. (See
pages 9 ~ 11 for detailed information.)

Service Adjustment-1

1. Enter the Service Menu
While pressing the MENU button on the television, press the Number Key 2 on the remote control unit.

The Service Menu now appear.

LB6A VER1.14
NO. NAME DATA

Item No.

00 RFAGC 17H XX010111

1.11101111 2.11111000

MENU

Status Register Bit Allocations

[ Service Mode Display ]

Item Name

Data value

2. Service Adjustments:
Press the CHANNEL UP/DOWN button on the remote

control handset to select the desired service menu
item you want to adjust.
Use the VOLUME + / - button to adjust the data. The
+ or - button will increase or decrease the data
sequentially.

3. Exit from the Service Menu
Press the MENU button to turn off the Service Menu

display.
The data which is set in the service mode is stored
into the memory IC automatically.

VOLUME

CHANNEL UP

-

CHANNEL DOWN

VOLUME +

-9-

-9-

MENU