GE PANDA Service Manual page 88

Chapter 4: Troubleshooting
Troubleshooting Tables
4.4.2.5 One Bulb Does Not Light
Possible Causes
Bad bulb
Bad harness/ bad
socket
Open in lamp wiring
Short in lamp wiring
Bad socket
Bad harness
connection
4.4.2.6 Both Bulbs Do Not Light
Possible Causes
No Mains to
transformer
Bad Dimmer Pot
switch
Bad Fuse
Bad relay on Power
PCA
Bad transformer
4-26
Step Troubleshooting Procedure
1. Remove observation light assembly.
Disconnect bulb from socket. Test bulb with Ohm
2.
Meter (should be < 1 Ohm).
3. Replace bulb if continuity test fails.
Open rear cover and disconnect harness at J26 on
4.
Power PCA.
With all bulbs installed, check continuity at harness
5.
pins 1-3, and 2-4.
With all bulbs removed, check for open at harness
6.
pins 1-3, and 2-4.
If either continuity test fails, remove upper housing
7.
and troubleshoot wiring.
Disconnect 2 pin connector located behind bulb
8. socket. With new bulb installed, check continuity
through bulb (should be < 4 Ohms).
9. If continuity test fails, replace bulb socket harness.
Check that connectors at transformer harness
10. (J24), dimmer pot (J25), and observation lights (J26)
on the Power PCA are seated properly.
Step Troubleshooting Procedure
1. Check lamp wiring. (Refer to steps 4-6 above.)
Open rear cover and disconnect transformer
2.
harness (J24) at Power PCA.
Using DMM, check for Mains voltage at J24 pins 3
3. and 4 on the Power PCA with dimmer pot turned
on.
If no Mains, verify switch in Dimmer Pot Harness.
4.
(Refer to 4.4.2.3 above.)
If no Mains, check fuses F11 and F12 on Power
5.
PCA.
6. If fuses and Dimmer Pot OK, replace Power PCA
Re-connect transformer harness (J24) at Power
7. PCA. Transformer output must have at least one
good bulb attached to check output (lamp voltage).
Comments
Bladed screwdriver
East side bulb:
pins 1, 3
West side bulb:
pins 2, 4
Bulb socket
harness part #:
6600-1594-700
Comments
Service Manual