I have a Meteor with a stuck on lamp and I cant figure out the cause. The lamp that is having an issue is the Shoot Again lamp on the playfield. Coincidentally, the Same Player Shoots Again lamp is also on, however this one is very dim.

The game has LEDs in it and an altec lamp driver board.

I've tried a known working lamp board and have the same problem. So that leads me the conclusion that the lamp board is fine.
On the MPU, i swapped U10 and U11 (because they are socketed and easily swapped). This also did not fix the problem.

I unplugged J2 on the lamp board and attached a little test lamp that I have. It stayed on solid.

The Same Player Shoots Again lamp in the head has a grey and red wire going to one lug. The other connects to the ground. The Shoot Again lamp under the playfield has a grey and red attached to it as well. It also has a solid blue wire connected to a lug as well as the ground.

At this point I suspect its either an MPU issue or a wiring issue. However I'm not sure where to look.

Any ideas?

I tried a regular bulb instead of an LED. (actually the Same Player Shoots Again is a regular bulb). Regardless of whats in the socket, they stay lit.

I don't think its on the playfield because when I connected my test lamp to the pin on J2, it stayed on.

But I tried a different lamp board and had the same problem. So it cant be the scr

It can't be the harness. If I test it at the board it's on solid.

Let me check and report back.

Disconnected j2 and j4 from the lamp board. Using my test lamp, the pin on j2 (pin 21) is still on all the time.

I have a logic probe ordered and on the way to see if something is strange with the data getting to the board.

I'm going to try and run a separate wire to that socket to see if its shorting somewhere.

One other note, with J1 unplugged from the lamp board, the same player shoots again light goes on and off in attract mode as I believe it should.

I thought I found it, till I didn't. So there are 2 grey and red wires. One goes to the pf. One goes to the backbox. It looks like they are swapped in the connectors. The one that's supposed to go to the pf went to the backbox and the one that was supposed to go to the backbox went to the pf. So I reversed the wires. When only J1 is plugged in, the backbox light flashes in attract mode. When only J2 is plugged in, the pf light flashes in attract mode. However, when BOTH are connected, the lights are on solid.

If I connect one of the connectors (eg J1) and run a jumper from J2 to the other socket, both lights light solid. (Same if I reverse it)

I'm going to put together another little bypass connector to take the harness totally out it it.

Bypassing the harness and running lines from j2 and j1, BOTH lights go solid when both are connected

To close the loop on this in case someone else has a similar problem - I found the problem!

I found that when the backbox ground was used, both the lights were always on. I disconnected the blue wire from the ground on the control lights and hooked directly to it (essentially bypassing the wiring in the backbox). Both lights locked on. This told me that it wasnt the wiring or a socket in the head.

I tracked the blue wire and it connects to J1 on the rectifier. The schematic showed that connection should go to pin 7. However on mine it went to pin 8. It seems that the replacement rectifier board has 9 pins instead of 8. I suspect whoever repinned that connector just counted spots from the end of the connector instead of counting from pin 1.

I moved that blue wire from 8 to 7, and the white wire from 9 to 8.

This fixed the problem I was experiencing.

Looking at the schematic, pin 8 is for the general illumination. Pin 7 is for feature lamps.

Thanks to slochar for giving me some ideas to try.

Yah it was very strange and coincidental that everything ran as well as it did.