3-6-2. High Light Condition; Ik Protector Check; Hold Down Check; Restoration - Sony Trinitron KV-29DRC420 Service Manual

3-6-2. HIGH LIGHT CONDITION

Input Video Signal:............................................................All White Signal
Picture level:..............................................Picture/Brightness Adjustment
1. Short across C8002, C8021, C8052, C8012, and C8015.
2. Set ABL current to 2.76mA by adjusting picture and brightness
towards max condition.
3. Adjust HV to obtain 33.6 ± 0.15kV (KV-27HS420/29DRC420/
30HS420 only) or 34.5 ± 0.15kV (KV-32HS420/34HS420/36HS420
only) by precision RV1 jig.
4 Remove short from C8002 and confi rm that hold down activates.
5. Short C8002 again and confi rm that HV recovers.
6. Re-adjust HV to obtain 31.2 ± 0.2 kV (KV-27HS420/29DRC420/
30HS420 only) or 32.2 ± 0.2 kV (KV-32HS420/34HS420/36HS420
only) by precision VR1 jig.
7. Remove shorts from C8002, C8021, and C8052.
8. Confi rm that hold down does not activate.
9. Remove short from C8012 and C8015.
10. Remove VR1 jig from DZ board

3-7.IK PROTECTOR CHECK

Input Video Signal:............................................................All White Signal
Picture level:...............................................Picture/Brightness Adjustment
1. Short across C8015.
2. Set ABL current to 2.76mA by adjusting picture and brightness
towards max condition.
3. Confi rm that AC Relay shuts off.
4. Remove short from C8015 and Short across C8012.
5. Turn the set off and on to reset AC relay latch.
6. Confi rm the voltage at CN5009 pin 8 (H_prot) = 3.6 ± 0.5V.
7. Remove short from C8012.

3-8.HOLD DOWN CHECK

1. Using an external DC power supply, apply 5.3 + 0.5 Vdc
between Pin 2 of CN507 (jig connector) and ground (Pin 8) on AY
board.
2. Confi rm that hold down activates.
3. Remove the external DC power supply.

3-9.RESTORATION

1. Re-solder CN5001 pin 1 and CN5009 pin 8 to restore AY-DZ
connections. (Or as applicable, restore AY–DZ connector by
carefully pressing the tab back into the slot and snapping the
connector shut. Be sure the tab is fl ush and level with the other tabs
on the connector.)
2. Remove jumper wire from MY board connection CN2304 pin 1
to CN509 pin 1.
3. Remove current meter from ABL pin and restore ABL pin connection.
4. Replace all DZ board screws and restore user menu settings to reset
condition.
KV-27HS420/29DRC420/30HS420/32HS420/34HS420/36HS420
KV-27HS420/29DRC420/30HS420/32HS420/34HS420/36HS420
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