shorted d3 or d4 would be my guess. Meter set to diode test, check across them each direction. If it reads short in both directions, bad. Check all the diodes in the HV section.

Unplug the displays too until you get the power correct. 3J5 on the PS feeds the display.

The FirePower manual on IPDB has a good schematic for this power supply.

The bridge rectifiers mounted against the back wall cabinet head are for the the feature lamps and for the solenoids. They shouldn't have any effect on the displays. Black wires on those bridges are the negative pin. Wile you want the feature lamp bridge negative lead to be the black wire also connected to the feature lamp smoothing cap, it shouldn't really matter if they where rotated as the grounds would be common at the driver board.

The rectification for the HV is D3 and D4 on the power board. I always start with checking rectification diodes when fuses are blowing instantly.

If the displays went out after ripinning the boards. Check j1 and j5 of the power board. See the firepower manual on IPDB and check page 13 for the power supply and page 23 for the power wiring.

Hi Ed,

Open the coin door and power cycle a few times quickly. If it never goes into attract mode there is a problem with the 5101 RAM or the memory protect circuit(s)

If it goes into attract mode, battery problem.

Good luck,
Andrew

There is a memory protection switch on the coon door, so it has to be open. Make sure the coin door stays open until you get a successful boot up to attract mode and keep the door open when setting audits. What happens is the computer checks a specific section of the RAM looking certain check value to be written there. If the RAM does not have the the check value that the computer expects, it assumes the RAM has been scrambled and it needs to be set to defaults. What it does is it starts audit mode and sets a flag into the RAM that tells the computer to do a factory reset the next time bootup.

Best course of action after changing batteries / going to NVRAM is to leave the coin door open. Power cycle a few times until you get attract mode. Then you can set your audits up the way you want. If you don't get attract mode before setting your audits, you risk having the "restore factory defaults" flag still being set in the RAM which will reset everything next bootup erasing your audit setup work.