Tron MCR power

Encom

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I'm working on a Tron with a power problem that I can't quite pin down. The problem started when I plugged it one night to find out the power plug itself had a short in it. None of the fuses in the game popped. I replaced the plug and checked out the supply and I am getting the 12 volts but I am getting between 2.5 and 3 volts on the 5 volt line with or without the boards connected.

I've tested with other power boards (some have the reset disabled) and they always have the low voltage. All of the boards test good in other games. I also swapped the filter assembly that has the diodes and caps from another Tron and still get the same low voltage. When I measure the voltages from the transformer itself, they are all there but measure about 1 volt higher than what is noted in the manual.

Any one have any suggestions on what to try next?
 
Yeah, all of the supplies work. When I drop one in another Tron or a Spy Hunter they work fine and I see five volts with the meter.

I think it is in the transformer brick too but I seem to be getting everything I should out of the brick. The one strange thing is that I can see the reset line pulsing, even on the boards that have the reset disabled. It swings from 0 to 12 volts on the reset. I'm thinking that I am probably seeing the same thing on the 5 volt line and the meter is averaging it out to 2.5 or 3 volts. It acts like a bad bridge rectifier or diode in the power supply but I've already tested and eliminated the diodes. There just isn't much left that could be bad. Maybe the cap that is across the primary side of the transformer?
 
Thanks, I was hoping that someone else has seen a similar problem with it. I was blaming that cap. Where did you find a replacement?
 
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