Working on a Stern Grand Prix that wont boot up all the way. Picture shows where it sticks every time. I have 5 volts on one pin at C2. I have also tried the reset button on the board.

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Night bump

All of the Led's on the driver board & MPU board are lit when game is turned on. Led 1 on MPU board comes on at power up then it flashes seven or 8 times, then stays lit. I also edited my first post , meant to say at C2 instead of C32

Also to note I read somewhere in another post about White star boards having an adjustable pot to adjust the 5 volts. On this game that spot on the board is unpopulated.

When the game is turned on L204 flashes once then stays lit. When I disconnected the ribbon cable that runs from the MPU board to the display board , the display as shown in the picture from my first post where it just says Stern Pinball Grand Prix on the display that stops flashing and is constant. Otherwise when that ribbon cable is plugged in the display flashes. I was looking in the wrong place for the adjustable 5 volt pot so Thanks much for that picture. Posting two more pics the first one shows what R16 looks like, I am not seeing how that can be adjusted ??? and No the game has never worked for me. Its not mine it belongs to someone else & I am trying to get it fixed for them.

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Posting a second picture of R16 because the first one was blurry. There is what kind of looks like a curved arrow on it pointing to the left with white paint over it. Perhaps its a slot and is adjusted via a small flat head screw driver there ?

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Boards look clean and good to me , and batteries were relocated by someone before me. Also ribbon cables appear to be oriented correctly. The five volts on pin 1 at C2 was just a little bit high so I set it to exactly 5V but it didn't help so I set it back to 5.043. I also tried a new 20 pin ribbon cable that I had in stock between the MPU and the power driver board just to check but the issue still persists

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Wow and Geez & Thanks!!!! so embarrassed !!! I Did Not see that I looked for corrosion under the battery part of the board only need to pay more attention

I think the battery pack is rigged to run only 3 but will also double check that tomorrow as well. Thanks much Grumppy & YeOldPinPlayer AC/DC Rocks!

Ok getting back to this I attempted to to reseat the chip at U213. When I removed it the two bottom legs came right off. I will get one ordered and see where that gets me. I also now have a Sopranos with the same board set that is doing the exact same thing as the Gran Prix it wont boot up all the way. Over the last couple days the Sopranos was partially shutting down losing the display altogether and an you could hear a relay clicking. If you reset it it would be fine for awhile not sure if its related or not but thought I should mention it. I now have two games on my plate with the exact same symptoms.

Blurry will get better pic

I have checked for corrosion on the chips to the right & cant see any sign of corrosion issues there. Today the new U213 chip arrived. I installed it and still have the same problem. So I guess that wasn't the issue but it still needed to be corrected. I am ready to send the board out for repair if needed. However I am still uncertain of what exactly the problem is.

Yes I did & Thank You grumppy for all of your help with this. I cleaned that leg at U413 but like you say it may be so far down in and under there that I cant see it all.I Will inform the owner and go from there.

Had the board repaired by a gentleman who does excellent board work> Game plays great now, Thank you to all who offered help.