Regulated 5v supply problem for Mr + Mrs Pacman pinball

TheShanMan

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Regulated 5v supply problem for Mr + Mrs Pacman pinball

I'm getting about 5.4v at the regulated 5v supply test points, and thus the game is not booting. The unregulated 11.9v supply is measuring over 15v. I've replaced the bridge rectifier diodes for the 11.9 supply and installed a rebuild kit for the 5v regulator circuit. No change! What's up???

Power supply board is AS-2518-54 and solenoid/regulator board is AS-2518-22.
 
Thats exactly what im saying. 5.4v is perfectly fine. The unregulated voltage is just that, its not going to be right on spec.
 
BTW, tell us how many flashes you get when it turns on? You should get a little flicker that's very fast when you first turn it on, then after a pause the led will light up a certain number of times.
 
I guess I was thrown off by reading in my bally pinball repair manual that the 5v regulated supply has to be 5.25 or less.

Which light? On mpu or squak? Mpu light just comes on solid - no blinking. I assume you're asking about mpu, but the squak blinks once, then 3 times, then twice.

There is some acid damage but the batteries have been off board for at least as long as I've owned the game (1 year).
 

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  • 2010-09-27 Pac Pin MPU Board 001.jpg
    2010-09-27 Pac Pin MPU Board 001.jpg
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The MPU is not running. It should do a series of blinks on bootup then go off. If its staying on you have issues. More than likely its caused by acid damage.
If you need it repaired PM me.
 
Yep, I knew it wasn't running, but the manual implied that it wouldn't run at voltages like I was seeing, hence going down the apparently wrong path. I appreciate the input!
 
For whatever reason, the bally games that I've had always ran a little hot. I even had one that was running at about 5.6, but booted every time.

The corrosion looks bad enough to stop that board from booting; it looks like nobody's ever done anything about it. If you cut off the battery, it doesn't really stop the damage where it is... the alkaline has a way of creeping. It gets worse and worse if it isn't neutralized. Basically you need to replace most of the stuff on the bottom 1" or so of the board, send it to Riptor and he'll do a good job for you for a good price, or you can do it yourself if you have the patience. Your problem will probably be in the three transistors on the bottom, and the sockets for the 5101 ram, and the socket for U11, and the ground traces running to all that stuff.
 
I would prefer to do the work myself. Pulling the mpu board, it is obvious that corrosion is a big issue, and probably the issue. Here is a better pic illustrating the corrosion. Would you guys say that the GPE repair kit should be enough or is there anything else you'd recommend replacing based on this pic?

Also, I read the pinrepair page on repairing the corrosion on this board (thanks wrongdon - I've seen the page before but glad you reminded me of it). I will take the steps listed there to eliminate the corrosion on the board.

2010-09-27PacPinMPUBoard003.jpg
 
Yes, Ed's kit should be everything you need in most cases. Make sure you pull the 5101 ram socket and check the traces under that. Also check the trace heading north that goes to the corner of the lower PIA(6821).
If I recall Ed sells two kits. One doesnt include the 5101 ram so if you think you need that make sure you order the right kit.
When I do these boards I replace ALL the sockets. Just something to keep in mind when you order parts. Very little added cost for alot of piece of mind.
 
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Yeah, the full kit is what I was going to get. Dang! Just noticed that he's out of stock of both kits! Anyone else sell a kit like this? I guess I can piece my own kit together but it's definitely more hassle. I'll email Ed too just to see what the ETA is.
 
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