what transistor did you narrow it down to?

These LED displays consume lots of 5v rail current. You can have a situation where the game works with plasma displays, but you have 5v problem with LED displays do to the increased load on the logic voltage.

That is the 5v regulator. It powers the computer and your new displays.

Make sure your connectors are in good shape. Specifically the 12v connector pins between the driver board and rectifier board.

I can tell you the only issue I've had is really good service from Brett. Shoot him an email, he's probably got a good idea.

I would repin all connectors in older Ballys, new filter cap as well. Esp when adding pinleds which consume more current.

I just replace the power supply board on any machine before upgrading displays. For $80 - $100 depending on the year its a no brainer for improving voltage issues of many kinds imo.

Just with the foam. The displays have been perfect

I want to weigh in on this one. I have been in communication with PUSH600 and I am just as much a loss with this one as everybody. This design has been in production for years and typically at about 75% max brightness each display draws about 35mA. This would be a first for the 5v regulator to fail on the driver board.

When first developed there were problems with the 5v system, particularly if the driver board was an early rev with the 2A regulator on the board, and resets would occur.

I will continue working with PUSH600 on this problem. I would like to see this resolved as well.

Brett

The issue is probably that orange ground return wire. It burns at both the driver board and the rectifier board. If the OP replaces the connectors pins related the 12v bus and return, replaces C23 and ties the negative lead of this cap to master ground at the driver board, the issue would probably go away. The extra load from the displays is causing more more heat, the resistance goes up on the connector pin, and then the CPU board is not happy when the 5v dips.

I have seen that exact scenario happen with replacement LED displays in a Bally. I can't remember what brand they where.

Yet another reason I love your displays!!