I recently bought a Flash in pretty nice condition for $550. Must have been a later production unit as it has the System6 MPU. Previous owner had it professionally serviced. I installed LEDs for the playfield and playfield GI (nat white frosted flat tops, blue frosted flat tops for the guide lanes and drains, blue 8-LED #89s for the flashers). Guide lane plastics were mismatched, so I replaced them with new blue transparent covers. Backbox lighting will remain incandescent.
I decided since it only has 2 flashers, it needed a bit more pop, so I ordered parts to install 6 LED flashers under the cabinet. 8-LED #89s: Blues front and rear, nat white center.
I had the 6 flashers wired in and they were awesome. Got holes drilled in the cabinet, got the front and middle right side and left front flashers mounted. The wiring for the back and middle one on the left side were twisted around, so I unraveled them, tossed the back one to the back of the cabinet. Got the middle one mounted. Decided to power up and see how it looked, got no flashing. ????!!! Worked just a few minutes before. Right side rear was sitting in the hole, left side rear - oh %$#%. When I tossed it to the back, it landed with the + connector arm right on top of the cabinet ground strap. ^%$#$!!! Everything but the flashers work, so I must have roasted a driver chip or transistor. Bad thing is, I can't even find the flashers on the schematic to trace it.

Anyone know which driver chip or transistor feeds the flashers??

Thanks!

Thanks!!
Everything else works so I'm assuming it is not a fuse; they all looked good. Need to get my meter from the garage and check them though.

Replaced the 2n4401 and TIP120 (Q24 & Q25). Still no flashing. Bypassed the small resistor on the small board that feeds power to the flashers. Works fine. So, looks like I'll replace the resistor.

Thanks for that info Viper! The 1-ohm was bad so it was replaced and they all work fine now. Maybe the 330 is bad as well since the LEDs work as they should.
Six LED flashers were installed through the cabinet bottom, three along each side. I used 4 blue 8-led #89s at the corners, 2 bright white #89s in the center. The whites seem to overpower the blues, so next time I order parts I'll order several more 8-led blues.

Feel free - it's not my idea; I saw it done to a newer machine.
I am considering adding a couple flashers to the back box, maybe just #44s to backlight the lightning.

LED string?

Gotcha.
Kind of a PIA to wire, but I'd like mine only lit with the flash lamps. Lots of real estate there so adding a few shouldn't be too hard.

Maybe a silly question, but are some of the backglass lights supposed to blink; i.e. from the driver board? Specifically those behind/near the lightning? Mine are on continuously, but I've seen some that blink.
Or are those 455s?

Thanks. Glad that means no more board work to do, but bad since now I'll feel the need to install some additional LEDs around the lightning and install them in the flash circuit.