Part one of looking at restoring a classic Atari 2600 I bought from eBay. In this part I have a first look at the power supply and start to think about any other issues I come across.
The Mosfet is in fact a voltage regulator ic. The 7805 was common around the introduction of that tv game. Power Mosfets became common one to two years later with their introduction to audio amplifiers. Could use the 2A S version of the ic as the logic at that time tended to be current hungry.
I am pretty sure you left the iron on that mosfet too long and killed it.. Early transistors die in 2 ways ( Too much heat) and (Incorrect Polarity on the power supply)
