DOWNLOAD Sony GDM-F400 / GDM-F400T9 Service Manual ↓ Size: 4.82 MB | Pages: 58 in PDF or view online for FREE

2-4

CN801

4

5

6

3

2

1

Four screws
(Tapping screw 5)

Three screws
(+BVTP 3 x 10)

H board

Remove wires from the 
purse lock.

Picture tube shield 

Knob (Menu)

Bezel

Before removing the bezel, secure the 
picture tube by attaching two screws to 
the picture tube shield at the positions 
shown with an arrow (diagonal two 
places) to prevent the picture tube from 
falling. (Use the screws +BVTT 4 x 8 that 
fix EMI shield.)

3

When one side of the rubber cap is
separated from the anode button, the
anode-cap can be removed by turning
up the rubber cap and pulling up it in the
direction of the arrow 

c

.

•

1

Don’t hurt the surface of anode-caps with shartp shaped
material!

2

Don’t press the rubber hardly not to hurt inside of anode-caps!
A material fitting called as shatter-hook terminal is built in the
rubber.

3

Don’t turn the foot of rubber over hardly!
The shatter-hook terminal will stick out or hurt the rubber.

•

NOTE: Short circuit the anode of the picture tube and the anode cap to the metal chassis, CRT shield or carbon painted on the CRT, after

removing the anode.

•

1

Turn up one side of the rubber cap in
the direction indicated by the arrow 

a

.

2

Using a thumb pull up the rubber cap
firmly in the direction indicated by the
arrow 

b

.

• Remove the bezel.  (Refer to 2-7.)

2-5

GND (DY)

P2

P4

1

2

3

5

6

4

Picture tube

Three connectors

A board

Neck assembly

Anode cap

Deflection yoke

2-6

CN2601

CN2603

CN801

P4

P2

CN509

CN502

CN510

CN701

CN501

CN504

CN506

CN505

CN601

CN602

CN507

CN503

CN402

CN412

CN401

CN403

CN408

CN407

CN405

CN406

CN404

Stand

H board

US board

Picture tube

Rear shield

FBT

AC inlet

A board

I/O terminal board

D board

When replacing or repairing the shown below table, the

following operational checks must be performed as a

safety precaution against X-rays emissions from the unit.

*

Confirm one minute later turning on the power.

1) Confirm that the voltage between cathode of D913

on G board and GND is more than 25.5 V DC.

2) Confirm that the HV protector circuit works and TV

Raster disappears when apply the voltage less than

34.2 V DC between cathode of D913 and GND using

an external DC power supply.

Part Replaced (

])

D Board T901(FBT), IC901,

R903, R922, RV901

•

 Mounted D board

D Board T901(FBT), R927,

R920, C923, D913,
D916, R935, R936

•

 Mounted D board

D Board R933, R932, R934,

R923, R928, R939,
R918, R053, IC901,
D918, D901, D902,
T901(FBT)

•

 Mounted D board

HV Regulator
Circuit Check

HV Protector
Circuit Check

Beam Current
Protector Circuit
Check

3-1

Part Replaced (

[)

RV901

HV ADJ

Apply 4.7 V DC to the connection point of R932 and

R933.  Connect constant current source to the FBT !¡

pin (–) on the D board and to the GND, then confirm

that when 2.0 mA is flown, the beam protector circuit

operates and high voltage value drops over 1.0 kV.

Connect constant current source to the FBT !¡ pin (–)

on the D board and to the GND, then confirm that when

1.7 mA is flown, the beam protector circuit operates

and IIV value (CRT anode voltage) is below 1.0 k

VDC.

Or, confirm that the raster disappears.