KV-20FS100 - Sony TV Service Manual (repair manual). Page 14

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 R565 component marked with X. 

+

IABL

ABL

T585

FBT

range

-

amPmeter

3.0 mA  DC

A

Note: The following adjustments should always be performed when 
replacing the following components, which are marked with Y on the 
schematic diagram on the A Board:

   A BOARD: 

IC600, PH602

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

2.  Input a DOT pattern at Q.C.

3.  Set the PICTURE  and the BRIGHTNESS controls to minimum.

4.  Confi rm the voltage of A Board between TP-23 & Ground is <135.6 

± 1 VDC.

5.  If step 4 is not satisfi ed, replace the components listed above, then 

repeat Steps 1 – 3.   

3-1. X R565 CONFIRMATION METHOD  
(HV HOLD-DOWN CONFIRMATION) AND 
READJUSTMENTS

The following adjustments should always be performed when 
replacing the following components which are marked with Y on the 
schematic diagram:

Part Replaced (   )

Adjustment (   )

DY, T585, CRT, IC001, IC561, 
C507, C508, C506, T511, L510, 
C588, L588, C566, C561, C563, 
D567, D568, D566, R567, R568, 
R565, R566, R562, R563, R561, 
R528....................A Board

HV HOLD-DOWN
R565

1.  Using a Variac, apply AC input voltage: 120 ±2 VAC.

2.  Turn the POWER switch ON.

3.  Input a white signal and set the PICTURE and BRIGHTNESS 

controls to maximum.

4.  Confi rm that the voltage between C566 (+) or TP30 and ground is 

more than 97.0 VDC for 20” and 105 VDC for 24”. 

 

1.  Connect the current meter between Pin 11 of the FBT (T585) and 

the PWB land where Pin 11 would normally attach (See Figure 1 
on the next page).

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

minimum: IABL = 100 ± 100µA.

3.  Confi rm the voltage of A Board TP-23 is 135.6 ± 1V.

4.  Connect the digital voltmeter and the DC power supply via Diode 

1SS119 to C566 (+) and ground (See Figure 1 on next page).

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 < 117VDC).

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

maximum: IABL = 1350 ± 100µA.

9.  Repeat steps 4 to 7.