Originally Posted by Captainmeme
Thermal issues can be found by spraying the suspected component with freeze-it.
Chemtronics Freeze Sprays
Or a similar product. Use your finger to narrow the suspects down then hit that area with a short blast. Unit come back alive? You may have to spray, power down and then back up incase there is a lock-out or foldback mechanism at work. Processor detects a fault condition then locks out operation or the power supply detects over current then folds back the current .
The unit does not power on (warm up), then off (cool down), then on again, with power continuously applied.
Once it powers off, it absolutely will not turn on again, unless you remove power
from the unit for at least 2-5 minutes. The longer you remove power, the longer the unit operates before it dies again. That's why I don't think it's a faulty solder. I think it's a faulty component on the board.
What you say about a lock-out may very well be true, but I think it's unlikely. These units are very old, and very simple.