Machine was fine when last switched off. Now, when switched on, no lights, no DMD, nothing at all except speaker hiss. Some LEDs on power driver board are lit up, but no LEDs on CPU board light up. So I guess CPU board has no power but not sure why. I tried reseating power and ribbon cables, no help. Any thoughts?

Thanks,
Jack

Hey Chris. The LED labeled 5V on the driver board is NOT lit up. What does that indicate? There are two other LEDs labeled "led 2" and "led3" that are also not lit. All other LEDs on driver board are lit.

Thanks,
Jack

Ok, so fuse F113 for the +5V logic was blown. I replaced it, turned on the machine, DMD indicated it began to boot and the 5V LED on the power driver board came on, as well as LEDs on CPU board, but after about 2 seconds the fuse blew again. What now?

So I unplugged J114 (power to CPU board), J116, J117 and J118, and when I power up, the fuse still blows. So it seems pretty sure it's a board problem, probably BR2 like you say. I guess it's time to send the board for repairs since I don't tinker with board repairs.

Thanks for the link. I've never tested a BR but ill give it a shot when I take the board out. I'll give a full report

Anyone know the exact part I need to replace BR2? I'm seeing several BRs at GPE, but not sure which exactly. After getting quotes for board repairs, seems like something I can handle for a few bucks maybe.

http://www.greatplainselectronics.com/search.asp?pg=1&stext=bridge+rectifier&sprice=&stype=&scat=

Thanks,
Jack

Yes. No. Yes, sort of John you're probably right.

Ok Chris, I'm taking some measurements with my DMM as per the link you sent. I have my red lead in the OHM slot, black in the COM slot, range set to 20M. Here's what I'm getting on BR2 (referencing the steps in the image in your link):

1) meter reads 0.00
2) 9.23
3) 1.35
4) 15.6

I don't really seem to be getting the nominal ranges described at the link. Also if I lower the range I don't seem to get much for readings. Other BRs on the board test various values, from 7s to 16s, but no where else do I get the 0.00 reading. Does that indicate the problem with BR2?

Thanks for any additional insight.

Jack

Ok John convinced me to let a pro handle this, sending the board along with another board that needs some fixin' in. My machines are from the early 90s and I've been having a lot of board issues in the last couple years. In fact, the only boards I haven't sent it for repairs are now the sound boards. Think it makes sense to send them in for preventative maintenance while I'm going through the pain of shipping and having my machines down? Or "if it ain't broke..." ?

Sent the board to Clive and he did a great job as always. It was a bum br2 plus he fixed several other things. Game is running like a top now. Thank you all again for helping me troubleshoot.

Jack