Interesting topic, as I have many pins of this era and the 'reset' is always something hiding, waiting to creep up and bite you. Long story short, I had a reset issue even after doing a lot of the heavily documented checks and balances. Bought a daughter board and it worked for about two years. Then, it started resetting again. Voltage was dipping below 4.7 even after all the fixes and daughter board. After telling a friend about all the work I put in to keep the voltages up, he suggested replacing the connector and seat on the board. That was the fix! I gained an extra .1+v raising it to 4.8v after having new, non worn pins installed. With the daughter board, my voltages were 4.9v.
Just goes to show you how many different angles you have to look at to find the actual gremlin.