Problem Description:
The Main Floor Double Bonus When Flashing light (L19) will not light during test or gameplay on Gottleib Haunted House System 80.

Things Tested:
1. Lamp is not burned out.
2. The lights on either side work. The rail has 6V. L18 which is on the same IC works
3. Good continuity between power rail and socket.
4. Good continuity between wire and A3-J3 connector.
5. Good continuity between connector and pin on A3 Driver board.
6. Pulled Driver board. Good continuity between pin and leg on transistor.
7. Tested transistor (Q20) in diode mode and received a reading of .623V and OL on all other pins which is consistent with all the other transistors.
8. Good continuity from transistor to resistor.
9. Resistor (R20) tested to .989 K Ohms same as the other resistors.
10. Good continuity from resistor to IC Z5.
11. No voltage between rail and wire that leads to connector. I do get voltage on the other lights.
12. Resoldered both connections.
13. Fuses good

Conclusion:
It seems that the L19 lamp is not completing the circuit when it should i.e. no voltage when supposed to be energized. It seems for some reason the transistor is not changing states to complete the circuit. Is it a bad transistor or something else not triggering the state change? I suspect it might be the Q20 transistor but it seems to have tested fine unless I am not testing it properly.

There only thing I have not tested is grounding the socket to the GI and see if it lights up to prove its not the socket but I have good continuity between the socket. I have no other driver or MPU boards to test.

Ideas?

Thanks!

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Installed a Pascal board and I still have this issue so it must be something in the wiring between the socket and the connector but I know I have good continuity

Got it working. It was not the inside of the socket that seemed to be the problem. I unsolderd the lamp socket. Hooked it up to my bench power supply and it lit fine. I sanded down all the outside contacts. Soldered it back in and walla it works now... guess was just a bad connection at the socket but I had continuity perhaps not good enough.... dunno

Thanks!