STUCK.. PP2 Atari brick has power, when plug into either AR2, DC drops big time???

[Nondrowsy]

STUCK.. PP2 Atari brick has power, when plug into either AR2, DC drops big time???

My Pole Position cockpit was playing fine for years. Then it just crapped out 2 days ago. I started at the power brick. Getting all the correct voltages with nothing plugged in 13.4VDC on pins 1,2,3. 35.6AC on pins 6 and 7. and 5.5AC on pins 8 and 9... I tested it Exactly as DOkert did in his youtube video. When I plug the J5 into the brick, I get 13.4VDC at the molex to the AR2's when they are not plugged in. What it's supposed to be right? As soon as I plug Either one in to Either AR2 (that is not connected to the board) the DC drops to 1.4... It's like either AR2 is draining the DC to ground? and it's not plugged into anything else at all. No noticeable damage to either AR II... What in the world could have happened and where to go next?

I think it's highly unlikely that both AR2's went out at the exact same moment, but they may have. I have tested the BR and it tests out fine. Neg. lead to positive leg on diode test and I get 5XX on both ac legs. Pos. lead to Neg. leg and same on both AC legs. I did order 2 new big blues.. But I really think it's the at the ar2's....

The only thing I did when the game quit. (Monitor still worked but both red lights went out on the board) Was test continuity and it appeared that the +5 at the board possibly had shorted to ground at the edge connector. Would this cause both AR's to fail? Why would I be losing almost all DC when connecting to Etiher AR by themself?

ANY ideas or help is appreciated!!!!

 

[andrewb]

Test your big blue. Measure the AC on either 10.3V DC test point on either AR, with the AR plugged into the brick. If it's above 0.500V AC, your big blue is bad.


You could also have an issue with the AR's, but check the big blue first, as this is more likely a brick issue.

Also, check to make sure you don't have any burned connectors on the fuse block. Specifically the 20A one. If any of them look brown at all, that's your issue. You can cut the connector off, sand down the wire and fuse block tab, and solder the wire directly to the fuse block, which will solve the problem permanently. See this thread for details, esp post #17:

https://forums.arcade-museum.com/showthread.php?t=430405

(sorry for the huge pic, copied from the thread above)

 

[Nondrowsy]

Thank you for the response! I just tested AC at the 10.3VDC test point several ways with one plugged in, then the other, then both. Got 1.9VAC every time. I did do A Lot of reading after it went down, and it initially led me to the big blue. That's why I already ordered 2 new ones. But in testing everything, it got confusing.

I should get the big blue's in a few days. Fuses all look ok. I still should probably get a new fuse block though.. No burn marks, and they pass continuity test at the connectors. Thanks again for the help! I'll update when they arrive

 

[andrewb]

Don't replace the fuse block. One thing at a time.

In general, resist the urge to shotgun replace parts on these (and most games). In a vast majority of cases, it's possible to do some simple measurements and figure out what needs replacing, then replace only those parts. (And even then, with things like a fuse block, you really only need to clean the original one, vs replace it with a cheap Chinese repro, unless it is severely damaged or corroded.)

The trick to repairing these is divide and conquer, in terms of figuring out the unknowns, narrowing things down, and homing in on the problem. Replacing parts blindly without knowing they need it only costs you extra money, removes originality, and worst of all adds new unknowns, as it is very easy to mess something up anytime you replace a part (often without even knowing it).

In any case, 1.9V is too high. Your BB is bad. (Or at least one of them in this case, as you should have two.) You could try removing either one, one at a time to see if it makes a difference, as they both may not be bad. Or you can just replace both. Let us know once you replace them, but I think you'll be all set.

 

[Nondrowsy]

Don't replace the fuse block. One thing at a time.

In general, resist the urge to shotgun replace parts on these (and most games). In a vast majority of cases, it's possible to do some simple measurements and figure out what needs replacing, then replace only those parts. (And even then, with things like a fuse block, you really only need to clean the original one, vs replace it with a cheap Chinese repro, unless it is severely damaged or corroded.)

The trick to repairing these is divide and conquer, in terms of figuring out the unknowns, narrowing things down, and homing in on the problem. Replacing parts blindly without knowing they need it only costs you extra money, removes originality, and worst of all adds new unknowns, as it is very easy to mess something up anytime you replace a part (often without even knowing it).

In any case, 1.9V is too high. Your BB is bad. (Or at least one of them in this case, as you should have two.) You could try removing either one, one at a time to see if it makes a difference, as they both may not be bad. Or you can just replace both. Let us know once you replace them, but I think you'll be all set.

I replaced both big blues with new big blacks.. no change. Went back over everything again and it turned out that while testing the bridge rectifier I must have gotten the leads turned around and tested it the same way twice or something. One AC leg from the negative was flashing 1300-1800 then nothing. The other 3 ways of the testing showed around 550. I guess it shorted? Either way I ordered 3 new 50amp 1000 volt bridge rectifiers for like $8 for all 3 and put the new one in and it is back to working 100%!

I also did the ground and +5 mod to the board at all the test points while I had the game apart. Plays perfect with no issues so far!

With those new parts and the new wiring it should be good to go for a long time! I need it to be, I'm currently in a battle for the world record on test track over on Twin Galaxies. Thanks A LOT for your help! Appreciate it!