Picked up a firepower a while back. Getting around to getting it working, no boot, did the 40 pin and realized power supply caps were bad shape. decided to start at the beginning.

Went ahead with rebuild of power supply, trying to test with no connectors (besides power input) hooked up.

Replaced 4 caps, upgraded the 2 rectifier diodes and replaced the 5V voltage regulator and reflowed all the connectors. (mostly based on http://pinball.flippers.info/system6repairpart3.asp & other likely guides/advice around on system 6 machines)

Testing the power supply with nothing hooked up. I get 12v where I should, and 100v where I should on the output connectors

Had odd results, getting .6-.7v on the 5v connector pins. Tested it with the board unhooked and getting the same on the output pin of the voltage regulator (backside). Tried it with a different voltage regulator, same thing.

2 different brand new LM323K same problem. What am I missing?

Took this image from another thread.

Across bottom of D7 and D8 20v AC

Ground strap to fuse F5: 13v DC

Top of C16: 13v DC

Top of C17: .7v DC (this should be 5v as the output from the regulator)

Same result if I measure on the backside of the board, 13v on the input leg, .7v on the output side. Same result measured across pins 3J6-7 (5v) and 3J6-11(GRD)

D7 and D8 were already replaced with beefier (Diode - P600G 6A 400 PIV) C7 C11 C13 and C15 were also just replaced with new caps.

I've tried 2 different replacement LM323k and get .66 or .7 vdc.

Is there a reliable way to test them outside the board? What do I try next? A 3rd brand new regulator?

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2 different pinball vendors. Not Gpe. I had only tried the original before recapping. Will go back and try it again.

PXL_20210425_155705811 (resized).jpg

Put the original back in and guess what. 5v working again.

Time to start replacing connectors with trifurcon.