KV-32FV27 - Sony TV Service Manual (repair manual). Page 14

3-1. X R530, R531 CONFIRMATION METHOD  
(HOLD-DOWN CONFIRMATION) AND 
READJUSTMENTS

Always perform the following adjustments when replacing the following 
components marked with a Y  mark on the schematic diagram:

Part Replaced (   )

Adjustment      (   )

R387, R550, R529, R530, 
R531, R532, R533, D519, 
D520, D521, IC501, C531, 
C532, T503, IC351, Q301, 
R356, R359, R361, 
D302.....................A Board

IC643, R661.........G Board

HV HOLD-DOWN
R530,R531

1.  Using a Variac, apply AC input voltage: 120+2.0/-0.0 VAC.

2.  Turn the POWER switch ON.

3.  Input a white signal and set the PICTURE and BRIGHT controls to 

maximum.

4.  Confi rm that the voltage of more than 23.0 VDC appears between 

TP85 and ground on the A Board. 

1.  Connect the current meter between Pin 11 of the FBT (T503) and the 

PWB land where Pin 11 would normally attach (See Figure 1).

2.  Input a dot signal and set PICTURE and BRIGHTNESS to minimum: 

IABL = 2175 + 100/ -325 µA.

3.  Confi rm the voltage of A Board TP91 is 135 ± 1.5 VDC.

4.  Connect the digital voltmeter and the DC power supply to TP85 and 

ground (See Figure 1).

5.  Increase the DC power voltage gradually until the picture blanks out.

6.  Turn DC power source off immediately.

7.  Read the digital voltmeter indication (standard = 27.24 +0.0 / -0.1 

VDC) (KV-32FV27 ONLY), (standard = 27.24 ± 0.1 VDC) (ALL 
EXCEPT KV-32FV27). 

8.  Input a white signal and set PICTURE and BRIGHTNESS to 

maximum: IABL = 2175 + 100/ -325 µA.

9.  Repeat steps 4 to 7.

If the setting indicated in Step 2 of Hold-Down Operation Confi rmation 
cannot be met, readjustment should be performed by altering the 
resistance value of R530, R531 component marked with X. 

 

3mA DC range

+

-

+

-

A

+

-

FBT

TP85

T503
FBT

TP85

R531 R530

DC Power Supply

digital multimeter

ammeter

 

 

Always perform the following adjustments when replacing the following 
components, which are marked with Y on the schematic diagram on 
the G Board:

     G BOARD: 

IC643, R661

1.  Using a Variac, apply AC input voltage: 130 + 2.0/-0.0 VAC

2.  Input a monoscope signal.

3.  Set the PICTURE control and the BRIGHT control to  

 

initial reset value.

4.  Confi rm the voltage of G Board CN641 between pin  to ground is 

less than 136.5 VDC.

5.  If step 4 is not satisfi ed, replace the R661 on G Board and repeat 

the above steps.