KV-34FS200 - Sony TV Service Manual (repair manual). Page 15

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KV-34FS200
HOLD-DOWN READJUSTMENT
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
 
 
Figure 1
3-2.  B+ VOLTAGE CONFIRMATION AND 
ADJUSTMENT
Always perform the following adjustments when replacing the following 
components, which are marked with Y on the schematic diagram on the 
GK Board:
  
GK BOARD: 
IC600, PH602
Adjustment (Y)
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  
 
minimum.
4. Confi rm the voltage on A Board between TP23 and ground is less 
than 136.5 VDC.
5.  If step 4 is not satisfi ed, replace R530 and R531 on A Board and 
repeat the above steps.  
SECTION 3:  SAFETY RELATED ADJUSTMENTS
3-1.  X R565 CONFIRMATION METHOD 
(HV HOLD-DOWN CONFIRMATION) AND 
READJUSTMENTS
Always perform the following adjustments when replacing the following 
components marked with a Y  mark on the schematic diagram:
A BOARD: 
HV HOLD DOWN
R550, T503, T504, D519, 
IC501, R533, D521, R532, 
D520, C531, R529, R530, 
R531, C532
R530, R531
GK BOARD: 
IC600, PH602
Part Replaced (Y)
Adjustment (X)
PREPARATION BEFORE CONFIRMATION
1.  Using a Variac, apply AC input voltage: 120 +/- 2.0 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. 
HOLD-DOWN OPERATION CONFIRMATION
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 above).
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). 
8.  Input a white signal and set PICTURE and BRIGHTNESS to 
maximum: IABL = 2175 + 100/ -325 µA.
9.  Repeat steps 4 to 7.
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