Russtang
New member
Hello all,
My buddy has a centipede that is not working properly. Here are the symptoms:
White, rolling screen.
1, 2-player buttons lit up.
Random audio pulsing/buzzing.
Won't play blind.
Here's what I tried:
1. Put machine in test mode. No beeps or visible changes on screen.
2. Fuses on power board are all good.
3. Verified all voltages on main board.
5v was reading 4.7v. I adjusted the trim pot until it was 5.0. AC ripple is approximately 750mVAC. Reasonable amount of ripple, or new big blue needed?
36VAC on ARII board is measuring 18VAC with respect to ground. Not sure if I am measuring it correctly by going to ground.
All other voltages check out.
4. Removed edge connectors, used contact cleaner on them and reseated them.
5. Removed/reseated all main board socketed chips.
6. Removed ARII board.
All caps measure in spec out of circuit.
2N3055 power transistor verified good.
Q8 (+12v), Q9 (-5v), Q2 (tip32) check out ok.
Big power resistors check out ok.
Nothing looks burned or blown on the ARII, main board, power board. Any ideas on what to try next?
Thank you,
Russ
My buddy has a centipede that is not working properly. Here are the symptoms:
White, rolling screen.
1, 2-player buttons lit up.
Random audio pulsing/buzzing.
Won't play blind.
Here's what I tried:
1. Put machine in test mode. No beeps or visible changes on screen.
2. Fuses on power board are all good.
3. Verified all voltages on main board.
5v was reading 4.7v. I adjusted the trim pot until it was 5.0. AC ripple is approximately 750mVAC. Reasonable amount of ripple, or new big blue needed?
36VAC on ARII board is measuring 18VAC with respect to ground. Not sure if I am measuring it correctly by going to ground.
All other voltages check out.
4. Removed edge connectors, used contact cleaner on them and reseated them.
5. Removed/reseated all main board socketed chips.
6. Removed ARII board.
All caps measure in spec out of circuit.
2N3055 power transistor verified good.
Q8 (+12v), Q9 (-5v), Q2 (tip32) check out ok.
Big power resistors check out ok.
Nothing looks burned or blown on the ARII, main board, power board. Any ideas on what to try next?
Thank you,
Russ