KV-21FA210 - Sony TV Service Manual (repair manual). Page 14

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KV-21FA210
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 R565 component marked with X. 
+
IABL
ABL
T585
FBT
range
-
amPmeter
3.0 mA  DC
A
3-2.  B+ VOLTAGE CONFIRMATION AND 
ADJUSTMENT
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:       Y  IC604, 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 <136.6 
VDC.
5.  If step 4 is not satisfi ed, replace the components listed above, then 
repeat Steps 1 – 3.   
SECTION 3:  SAFETY RELATED ADJUSTMENTS
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, 
IC604, C507, C508, C506, T511, 
L510, C588, L588, C566, C561, 
C563, D567, D568, D566, 
PH602, R567, R568, R565, 
R566, R562, R563, R561, R528, 
R668....................A Board
HV HOLD-DOWN
R565
PREPARATION BEFORE CONFIRMATION
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 105 VDC. 
HOLD-DOWN OPERATION CONFIRMATION
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 138.0 ± 0.3VDC.
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 = 1650 ± 100µA.
9.  Repeat steps 4 to 7.
Y
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