Page 1 of 1

Black Hole Power Supply Board question

Posted: Fri Jul 04, 2014 10:44 am
by Baumann
Hey guys,

I posted this in the System 80 club on Pinside, but thought I would hit up the local crowd as well.

On my Black Hole, after a few games, the whole game will lock on the coil reset and the lower playfield 4 drop bank will lock the solenoid half way and hold it until I shut it down. I checked and I'm losing the +5 as the LED gets really low and sometimes goes completely out. The R12 wirewound resistor gets really hot. Hot enough to burn your finger. I pulled the board and started doing some troubleshooting and I think the Q1 transistor is bad as I'm showing a voltage drop from C to B and C to E. Both of those should read OL. What is weird is Q1 isn't in the same circuit as R12. Q1 is in the high voltage section. R12 is in the low voltage section. Can anyone with experience with this board explain to me what I might be missing here? Thanks!

Scott

Re: Black Hole Power Supply Board question

Posted: Tue Jul 08, 2014 9:41 am
by Baumann
Well, to answer my own question, I went ahead and ordered a component rebuild kit for this board. Figured it can't hurt to shotgun it and replace all the main components and then see what I have.

Scott

Re: Black Hole Power Supply Board question

Posted: Tue Jul 08, 2014 3:46 pm
by JohnH
It's not unusual for wire-wound resistors to run too hot to touch, so don't be surprised if that continues after the rebuild. The only way to remedy that is to use a higher wattage resistor.