Centipede cabinet died

[opt2not]

Most likely. Yes!

 

[mathewbeall]

Ok - pretty sure I found at least some damage on the AR2 board, but here are the voltages:

5v = goes between 4.6 and 4.8
12v = 12.1
-5 = -5.2
22 = 24.0
-22 = -25.1
15 = 15.3
-15 = -14.9

As I was looking for the 5v test point on the AR2 board, I removed it so I could see it better - and R30 is NOT doing well!

I still however can't find the +5v test point ( I see the -5). and I see a VR - I assume this is for adjusting the 5v.

My next step I think is to replace the burned out R30 and see what happens then. My guess is that there was a power spike that blew out the fuse (slow blow - F2) and caused this damage on AR2 as well.

 

[opt2not]

Yikes! That would do it.
I would also check the transistors on the heat sync. But that will require you to desolder them to properly test.

But try the resistor fix first, and I'd also continuity test the traces around it, in case the burn-out caused damage to them.

 

[mathewbeall]

Put the new resistor in place - still not getting 5v (4.7ish) to the PCB. I found a working AR board over at QuarterArcade. I will swap that in, and assuming all goes back to working, I will keep troubleshooting on this AR board to figure out what component is burned out.

 

[opt2not]

Did you look at the molex connectors as well? Anything burnt or discoloured on them?

 

[mathewbeall]

Had some messages back and forth with AndrewB over at KLOV. He had me check a few things, including the AC Ripple for the Big Blue (16.3VDC UnReg and Gnd test points on AR) - it should be less than .5v - mine measured about 3.5v, so I have ordered a replacement Big Blue.

Man - I hate waiting!

Matt

 

[opt2not]

Yeah I have a feeling the big blue is the culprit.

 

[8bitforlife]

@mathewbeall could you take a picture in detail how the wires under the big blue are connected. I'm not sure I connected mine right. I cant seem to find any proper pictures on this subject.

 

[mathewbeall]

you bet - next week when I get it in... i did watch some video's.... hopefully mine is similar - it looked like all of one color (purple) go to negative, and all of the other color (orange) go to positive.

Not sure if those colors are always the same - but I will take some pictures before I do anything and post them.

 

[8bitforlife]

ya mine slightly different I have 1 different color on each line and I wasnt paying attention the rest are black. I believe.

 

[stj]

replace the edge connector in the cab with a good quality DUAL-CONTACT SOLDER TERMINAL type after you fix the psu.

the original crimp contact connectors are junk - even atari stopped using them around 82'

 

[mathewbeall]

Hey @8bitforlife - I am still waiting for the capacitor to arrive, but here are pictures of my PS with the old one.

 

[ReplicaX]

Good olde Blue always causing problems

 

[8bitforlife]

@mathewbeall thank you very much that's perfect

 

[mathewbeall]

And, capacitor replaced - ALL good! I will also replace the large transistor in the middle of the heat sink on the AR next weekend - as AndrewB said that if it goes, it will take out the PCB - so might as well replace it to be safe with one that isn't 40 years old.

Thanks for everyones help - as usual! View attachment 27284View attachment 27284

 

[opt2not]

Awesome! I knew the Big Blue was suspect.

I had an Asteroids cocktail that gave me the same power troubles and the Big Blue was the culprit.

Glad you got it fixed.