Half the play field lamps of my RFM machine have stopped working. Diagnostics show all lamps on matrix 1 are out. All the fuses check out, and I've reseated all the connectors on the power driver board with no change. The schematics aren't being a lot of help—the connector they identify as carrying Matrix 1 power from the driver board isn't used on my machine (yes, all the lamps used to work, so it's not that something's plugged in wrong.)

Anyone successfully troubleshot a Pinball 2000 machine where an entire lamp matrix went dark?

Thanks for the suggestions. I'll have to dig back into the machine (which unfortunately I buttoned back up) and take a look at the things mentioned above.

My meter is showing 10.0V DC at the F111 fuse, using TP6 as my reference point, so way short of 18V. Checking against other test points on the board, TP4 says it should be 20V and I'm registering 22.4, and TP3 says it should be 50V but I'm reading 67.5V.

LED 3 is lit, and I'm showing 20.6V at TP1.

Thanks for all the help so far. I've got the machine opened up again, and here's what I'm finding:

- I'd said lamp matix 1 was out in my original post, it's actually lamp matrix B.
- The schematics I have indicate the connections between the lamps and the power driver board should be through J110. J110 doesn't have anything connected to it on my power driver board (it never has, and the lamps used to work, so I'm guessing the schematic is identifying the wrong connector.)
- The row of transistors with Q6/Q10/Q14/Q18/Q22/Q24/Q28/Q32 on my power driver board are bent over a bit, like they were pressed on hard at some point. Q6 in particular seems sway easier than other transistors on the board when light pressure is applied. As these are the column transistors for lamp matrix B, I'm suspicious the bending over of the transistors weakened traces or solder joints and over time one of them has given out.
- I'm seeing ~22V on the tabs of the row transistors associated with lamp matrix A. I'm only seeing 1.1V on the row transistors for lamp matrix B.
- Test point TP1 (18vA) is regsitering ~22V. TP2 (18vB) shows 0V. Is 18vB used on this machine?

At this point I suspect I'm going to need to pull the power driver board and perform continuity checks for the circuits associated with lamp matrix B, looking for an open. Any other suggestions for things I can try before pulling the board?

Your previous advice has gotten me into the neighborhood, now to nail this failure down...

Here's an image of my RFM power driver board with the partially bent over transistors highlighted.

RFM transistors (resized).jpg

Yes, although I would have sworn I'd checked continuity on all the fuses when I first started looking into the problem. I don't have any spares of that type so I tried swapping F111 in to see what happens. It blew as well, so I've got a short on that 18V circuit. Blown transistor that shorted internally, I'm guessing? At this point I think I'm going to have to pull the power board to be able to get access to the transistor leads. I probably won't make the attempt until after Thanksgiving here in the U.S., as I'm hoping to get some replacement fuses and at least have the machine playable (albeit without Matrix B lights) for company we're having over.

Thanks again for the help!

Good call, I measure a short across D33. I've ordered a replacement part and will be pulling the power driver board when it comes in. Thanks!