Bally MPU LED Stuck On (AS-2518-35)

RIK-666

Distinguished
Apr 24, 2009
2
0
18,510
Using my perfectly working mpu board in my Supersonic to repair a mates Paragon mpu I left a solder splash on pins 17,16 to pin 15 J4 shorting the 5 volt to the 43 volt instantly blowing f4 and locking on the LED,no flicker. Changed all usual parts and replacing the now working Paragon chips U11,U6,U9 still no good. Replaced Q1,Q5,Q2,VR1,CR44. If only I had have been a little less hasty and more careful I wouldn't be asking for help. I have no voltage present at TP6 on the mpu. When replacing known good U9 back into Paragon mpu and hooking up J4 to make sure it was still o.k. it now also had the same problem - LED stuck on, after close inspection I had bent pin 22 so it was not seated in the socket, reseated it and Paragon mpu back to a.o.k. Supersonic mpu LED stuck on. Can anyone help the idiot please???
 

RIK-666

Distinguished
Apr 24, 2009
2
0
18,510

Hiya, writing from Australia and my name is Marcella (RIK's GF)...sorry for the inconvenience: googled for 'pinball machine repair help/info' and Tom's came up, yes... Was the 3rd recommended on the 1st page and the 1st 2 didn't look promising at all. Also thought seeing it's more of an MPU prob and not pinball per se I thought he might find some info here, sorry if not - my bad.
BTW does this site originate in Ireland? Cheers, and again, my apologies if inappropriate.

PS Funny how Google works, often when I enter the same query I get different page results. :pt1cable: