Yesterday I was walking down the road where my car was parked and I noticed an orange TV in the dumpster…
Without hesitation I grabbed the TV and did a quick check: tube seemed OK, intact case and no buttons missing. The TV was, however, very dirty and had a bad smell.
Took it home and plugged it in: I got some white noise in picture and sound, so this was a viable restoration project.
After a good and thorough cleaning (I use “Mistolin” grease remover for these cases and it works great), I plugged to power and my CATV outlet. Unfortunately, the TV was unable to produce a picture – it seemed that V-sync was missing or bad.
Well, I opened the TV (WARNING: the tube will retain high power even after unplugged from power – do not open a TV unless you know what you are doing) and cleaned the PCB. I noticed a variable resistor in bad shape, so I cleaned it with contact cleaner. Also, I moved it around a few times. I ended up doing this on all variable resistors mounted on the PCB.
The result? A working Hitachi P-20 form 1973!
More info about this nice retro TV at Radio-Museum:
https://www.radiomuseum.org/r/weltfunk4_hitachi_p20.html