KV-27FS13 - 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 R564 component marked with X. 

+

IABL

ABL

T505

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: 

IC601, PH601

1.  Using a Variac, apply AC input voltage: 130 + 2.0/ -0.0 VAC
2.  Input a monoscope pattern.
3.  Set the PICTURE  and the BRIGHTNESS controls to minimum.
4.  Confi rm the voltage of A Board TP-600 is <136.5 VDC.
5.  If step 4 is not satisfi ed, replace the components listed above, then 

repeat Steps 1 – 3.   

3-1. X R564 CONFIRMATION METHOD  
(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, T505, CRT, IC501 C507, 
C520, C505, C509, C515, T504, 
T503, C551, L510, C546, C537, 
C547, D517, D518, D519, R560, 
R561, R562, R563, R565, R566, 
R567, R525....................A Board

IC301........................MA Board

HV HOLD-DOWN
R564

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 C546 (+) or TP503 and ground is 

more than 21.0 VDC (27/29 inch) or 23.0 VDC (32/34 inch). 

1.  Connect the current meter between Pin 11 of the FBT (T505) 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 = 1730 ± 100µA. (27/29 inch) or 2175 +100 - 325µA (32/34inch). 

3.  Confi rm the voltage of A Board TP-600 is 135 ± 1.5 VDC.
4.  Connect the digital voltmeter and the DC power supply via Diode 

1SS119 to C546 (+) 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 24.78 +0/ -0.1 VDC 

[27/29 inch] or 27.24 +0/-0.1 VDC [32/34 inch]).

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

maximum: IABL = 1730 ± 100µA (27/29 inch) or 2175 +100/-325 µA 
(32/34 inch).

9.  Repeat steps 4 to 7.