Repairing a Flight 2000. Wasn't getting correct voltages on my rectifier board so repinned the connectors, that didn't fix it so I bought a Weebly kit. Built the kit, installed it, plugged the game in to a power strip, flipped the game's power switch and then turned the strip on. Everything seemed to be working well until the varistor that's attached to the line filter started smoking. I plan on replacing the varistor but I want to figure out what I should check that might cause that. Besides a lightning strike I don't know what else can cause the varistor to blow, Attached photo of the rebuilt RB (before i clipped the keyed pins).
Next I plugged in just J2 and starting smelling something so I pulled the board to double check wiring. Checked transformer taps (two are double tapped not sure if thats normal but attached a photo just in case) and connections to board. Plugged it back in and the smell is definitely coming straight from the RB, began to increase over 30 seconds so I turned the game off and unplugged it. The F6 fuse was hot but not blown. Not sure what to do next as it seems unsafe to measure voltages, any help would be much appreciated!