I'm working on my radical, I was adding in the left VUK and accidentally wired the coil wire to the wrong wire in the auxiliary diode board, it Blew the transistor , pre driver, and 7408 for the shooter Kickout. The transistor, pre driver and 7402 blew for the bottom popbumper as well in an unrelated matter.

The displays were working after the fact.

I then replaced the components, triple checked all of my work, even socketed the ic's.

Now my displays are not coming on at all. And the "blanking" led is not coming on .

I checked all of my fuses (pulled them to check them) they are all good

Any help or ideas?

Any clues of the workings of the blanking signal or its circuit?

I know that U50 falls inline with the blanking signal and I replaced U50, I'll check in that area again, and again.

I replaced the 555 timer at U43, and its 2n4403 transistor at Q50

Still no luck,

Blanking led is still off

With my probe it ( u20 pin 2, u43 pin3 ) reads lo, then nothing after a few seconds

I checked all of my work thoroughly and all of the removal of components went smooth, no traces or solder holes lifted... soldering all looks great, checked for shorts, none. Check continuity on all of the traces, all good

Checked the one at u55, looks like the blanking is on pin 1, on boot it goes low, then nothing after a few seconds

Unfortunately, I'm great at replacing components, but still green on knowing what exactly to look for :/

Takes me a while to follow the schematics

On the other 7402 @ u45, I can't tell exactly which pin is the blanking signal

So, tonight I decided to start shot gunning the issue since at the moment I am stumped.

So I socketed and replaced PIA at U38

the 7402 at U43
the 7407 at U49

I also swapped the cpu with my working space station, and the cpu is working, I have not swapped roms out since space station requires sound roms.

the blanking signal LED is still out

I have several PIA's and sockets and other chips on order

anyone have any suggestions to offer?