Babypac man F1 communication test error

[ch0de]

Ok here i am again..

Baby pac man communication errors. when you push the coin door button you get trash on the screen. when you push the Vidiot test switch you get the communication test with all F1's down the left hand side. and nothing on the right hand side.

Here is what i have done.

Replace ALL .1" molex headers on Vidiot and MPU and Connectors on wires with crimp and solder type.

MPU - Replaced u8 Socket tried three different 5101 chips. replaced both u11 and u10 , rebuilt with a great plains corrosion kit (5volt detector), replaced all .1 headers

Vidiot: (i have tried two different vidiots with same results._ repalced u8, u1, u1, u3, u5, u4, u35, u6, u7 u13 and u14. Rebuilt the 12 and 5 volt regulators. reaplced Pots for video out and sound out. tried diffrent Romchips. diffrent u19-u26 ram.

And other stuff... What am i missing. were could this F1 error be.

 

[Dokert]

Pull your IC's back out and verify that no legs got bent under

 

[ch0de]

Oh i've tried that. I've also swamped out quite a few ICS off the MPU and Vidiot. The only IC i don't have another of is the 9928 and that is coming tomorrow.

I've run continuity on all the Ic's

 

[ch0de]

Tried a friends MPU (which has it's owns issues but in his box the communication works. and i get same result.

I'm going to try replacing u5 and u35 on my vidiot board today.. Hopefully the 9928 chips come in and it may be that.

Also getting new 5101 chips today also.

 

[ch0de]

So i got new chips from arcadechips.com today

I replaced the vidiot u6 9928, u19-26 4517, u8 6809


MPU: u8 5101, u7 6810, u9 6800, u11-10 6821


Same problem, F1 on the left side of communication test.

 

[ZEN]

Did you read that guide I sent you closely? Did you replace any sockets on bbypac, grab a flourescent light and verify traces are ok on vidiot....just trying to help eliminate stuff for ya

 

[ch0de]

I've read it over and over word by word, and that is how I've gotten it to this point.

I'm getting exact same results with both vidiot and MPU i have (all board with breand new chips. I'm thinking it is somewhere past those boards. Maybe the Power supply or the play field.. urg

 

[Riptor]

If the mpu had previous acid damage was the socket for the 5101 removed and replaced? The traces under this socket are commonly eaten away from acid.

 

[ch0de]

Yes the 5101 socket was replaced and all pins have bet trace from chip down board.

 

[channelmanic]

Make sure there are no solder shorts where you put wires on the board.

 

[ZEN]

I know you hate to hear this, but, also check you repinning work, my first header I had I crimped a wire a little poorly, redid it and that got mine going, albeit for a brief bit, b/c I found other issues, but that test is for communications from vidiot to mpu so it can be somthing simple too..

 

[ch0de]

I have run a continuity test on all 22 pins and they all get good continuity and 0 resistance down there trace. Thats testing from the chips pins to the first component down board.

The Socket was replaced as part of the rebuild kit from Great plains.

 

[ch0de]

I know you hate to hear this, but, also check you repinning work, my first header I had I crimped a wire a little poorly, redid it and that got mine going, albeit for a brief bit, b/c I found other issues, but that test is for communications from vidiot to mpu so it can be somthing simple too..

I rechecked this morning.. from spots down board on vidiot and MPU, so my continuity test ran from say end resistor down trace through Header though crip down wire through crimp , header, trace to first component (resistor or whatever). And i fallowed the pinout that is in the Babypac repair guide ZEN sent me.

 

[ZEN]

what chips havent you swapped,, on videot.?

 

[ch0de]

The questions should be what chips haven't i swapped.

here si what i've changed. all chips came new from arcadechips.com , Great plains, or mikes.

u1, u2, u3, u4, u5, u6, u7, u8, u13, 14, u16, u35 and all ram u19-u26

I don't have new EEprom yet thats on the way, but i have tried two sets of eeproms with same results.

 

[ch0de]

I think im going to ymake a test bech harness that connects just the cmmunication points between boards.

Has anyone seen com test show all f1?

 

[ch0de]

So i got it working past the f1.

It was a few Bad cable on the MPU j3 connector, Grounded out up by the coin door. Guess they got pinched together in coin door at some point.


Going to take a break then tackle some of the other issues.

Thank you so much for your help!