Tron missing 5v at pcb.

Grbgemen

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Recently rebuilt MCR 90412 power supply with kit from bob. Voltages all checked out okay after rebuild. Both 5v and 12v adjustable. Game was running fine. Power it up today and nothing on screen.

Starting at the power supply, with the pcb unplugged, I am getting 5.1v across C106. Testing for voltage at the harness going to the PCB, and I am getting next to nothing.
 
Check your molex connectors for pushed in pins. Also use a MM to check continuity from the PS to the PCB connector.
 
Check your molex connectors for pushed in pins. Also use a MM to check continuity from the PS to the PCB connector.

+1

Follow the wires from the power supply to the pcb there is something wrong with the wires, loose connection(s), pinched wire, cut broken. At this point your are only looking at the +5 so it should not be hard. If you turn off and unplug the game you can do a continuity test from the supply to the connector.
 
Do not see any wires loose, cut or pinched. Have continuity from plugs on power supply to the pcb connector.

The 5v is not getting to the molex connectors at J4 and J5. I do not see broken/cut traces or cold solder joints. Going to look it over again.
 
Still having issues with this. Not sure what my issue was before but I am getting 5v at the pcb connector. When I plug the PCB in, the voltage drops to around 2v.

The other day I was messing with it and the game booted up just fine. Earlier tonight, I turned it on and it played just fine also. However a few mins ago it was only showing 2v or so with the pcb connected. Without the pcb, its around 5.15v.
 
Still having issues with this. Not sure what my issue was before but I am getting 5v at the pcb connector. When I plug the PCB in, the voltage drops to around 2v.

The other day I was messing with it and the game booted up just fine. Earlier tonight, I turned it on and it played just fine also. However a few mins ago it was only showing 2v or so with the pcb connected. Without the pcb, its around 5.15v.

You really ought to disconnect the +5 wire from power supply and put one meter lead on the disconnected wire and the other lead on the edge connector where the +5vdc comes into the board. With the meter on ohms setting wiggle wires and connectors and look for changes.

I really don't think this is a pcb fault but I would check for anything loose or close to touching.
 
You really ought to disconnect the +5 wire from power supply and put one meter lead on the disconnected wire and the other lead on the edge connector where the +5vdc comes into the board. With the meter on ohms setting wiggle wires and connectors and look for changes.

I really don't think this is a pcb fault but I would check for anything loose or close to touching.

I have already done this. Reading never changes. Continuity on each of the 5v lines.

I know it is not a pcb issue. It's a power supply problem. I have 3 pcbs and all were working before.
 
Do not see any wires loose, cut or pinched. Have continuity from plugs on power supply to the pcb connector.

The 5v is not getting to the molex connectors at J4 and J5. I do not see broken/cut traces or cold solder joints. Going to look it over again.

The molex connector is where the voltage is missing and that is what I would look at first!
 
When i had my tron i rebuilt my ps.. worked for awhile and started dropping the +5...

i gave up on mine and put in a mikes arcade mcr power adapter with a HEAVY DUTY power supply.
 
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