I just picked up a High Speed. It has been sitting for quite a while and was very well loved/used during it's lifetime. Went to power it on and only get speaker hum and some GI lighting. There is some definite acide damage at the battery holder. At least 3 of the connectors corroded off. I don't see much downstream damage, but I also may not have the experience to notice all but the worst.
After some forum searches and some poking around on techniek.flipperwinkel.nl, I did a few tests.
All the fuses test good.
Power Supply Test Points:
1 = 9.4 v
2 = Ground
3 = 11.28 v
4 = -14.7v
MPU
TP 1 = Ground
TP 2 = 9.4 v
Pin 8 on UU15 - 8.9v
It looks like the PS is putting out too much power on TP1 and TP4, while slightly low at TP3.
I get no lights on the MPU at all. Since the game is only a few hours old to me, I haven't pulled the MPU and checked to see if supplying the correct 5v will power it on.
I am looking for suggestions on how to get the PS to supply the correct voltage. My experience has been mostly going from 0v to the correct voltage after replacing caps or such. Bringing down voltage is new to me.
Is there a way to tell if overpowering the MPU has blown something?
I am learning, but still very much a novice. Please don't assume I have done something obvious, as I may not know about it.
Thanks for any help you can provide.
Acid Damage (resized).JPG