I came across a cheap retro 1981 Grand stand Astro wars console on ebay, I had a nice idea about reusing its shell as a new console, as the listing said the screen was cracked.
Looking at the console the front plastic lens is cracked so there was some hope for the VDF screen inside being ok, I hooked up my bench power supply and hooked some algator clips to the + and – leads on the battery connectors, i flicked the power button on the front and the unit seemed dead no noise nothing.
I removed the 7 screws holding the case closed and it reviled 2 pcbs a speaker and a VFD screen, the screen looked fine and had no cracks, I applied power and using my multiemeter I probed about on the first green power in PCB and I had no voltage, I then looked for shorts and found the 9+ and GND pins on the green board where shorted.
The board being a simple single sided board it could not have a short on this side of the PCB
Removing the black shield over the screen revels the main pcb, most of the brains are under the screen, I did some more voltage checks and I found that SO2 and NPN transistor had its Base and emitter shorted.
I have a large horde of random electrical components, looking at data sheets for SO2 and NEC N882P, I did some digging in my stash of transistors and I found a ST ED136 wiht the same specs as the old NEC part
After swapping them out and applying power the unit sprang to life, with the screen working fine, its still nice a bright.
Its pain to get a good photo of the unit working but as you can kind of see the space ships are displayed on the screen.
Not a tearribly hard repair but its another item saved from the scrap pile.