Doctor Who
Bally, 1992Hey there everyone,
I have a Doctor Who that has been sitting for a few years that I want to get back into playing condition. I powered it up tonight, and F111 is blowing immediately upon power up. I pulled the power supply board and replaced BR4, put it back in the game, and the same thing happens. Any ideas?
Thanks,
Brian
Okay, with no connectors plugged in to the board except for J102 (power), it's still blowing. I hadn't checked the original bridge when I changed it, just assumed it was bad, but I just used my DMM and it appears to be okay. I guess I have a short somewhere on the power supply board? (I didn't see anything obvious...)
Quoted from RocketFromTombs:I guess I have a short somewhere on the power supply board?
Yes.
Quoted from RocketFromTombs:(I didn't see anything obvious...)
Shorted components can be invisible.
New BR4 good ? Then using your meter as best you can, go over the 20 volt section.
How's this ? 7812 -12V regulator ?
LTG : )
Alright, it took a while due to a busy holiday week, but I got it all fixed.
There was a trace from one of the AC inputs on BR4 that was shorted to ground (looked like a solder splash). Took a bit of searching to find it, but I got it. I replaced the 15,000 microfarad capacitors while I had the board out, they were original and a couple looked like they were starting to bulge. Put the board in the game, and it's alive! WOOHOO! I still have some issues with the mini playfield that I need to address (namely no motion CW or CCW) and a couple of opto switches that aren't registering, but aside from that, everything works, and I was actually able to play a game - it's been about 5 or 6 years since I got to do that!
Thanks so much for your help, I really appreciate it.
-Brian
Quoted from RocketFromTombs:Alright, it took a while due to a busy holiday week, but I got it all fixed.
There was a trace from one of the AC inputs on BR4 that was shorted to ground (looked like a solder splash). Took a bit of searching to find it, but I got it. I replaced the 15,000 microfarad capacitors while I had the board out, they were original and a couple looked like they were starting to bulge. Put the board in the game, and it's alive! WOOHOO! I still have some issues with the mini playfield that I need to address (namely no motion CW or CCW) and a couple of opto switches that aren't registering, but aside from that, everything works, and I was actually able to play a game - it's been about 5 or 6 years since I got to do that!
Thanks so much for your help, I really appreciate it.
-Brian
On the bi directional board under the pf that controls the mini pf is a cap. I am willing to bet it puked its guts out and took out some traces and possibly the chip on the board.
Wanna join the discussion? Please sign in to reply to this topic.
Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!
This page was printed from https://pinside.com/pinball/forum/topic/doctor-who-f111-blows-on-power-up?hl=rocketfromtombs and we tried optimising it for printing. Some page elements may have been deliberately hidden.
Scan the QR code on the left to jump to the URL this document was printed from.
Schoolcraft, MI