I removed the bottom cover and did a little more 91% Rubbing Alcohol treatment on the logic board (with hair dryer after), then removed the RAM modules and dipped the gold leads in the alcohol and then inserted/removed them a few times into each slot, then dried both the modules and the slots with the hair dryer. Reinserted the modules, plugged in power to make sure everything initialized right, then put the bottom cover back on and... voila! I am typing this reply, HOURS after doing that and it has not spontaneously rebooted even ONCE! Hallelujah! Praise Almighty God, in the Highest! Amen! Um, do I sound happy enough? :-D
WAS thinking of possibly trying to repair my son's Xbox 360S, by replacing the optical drive, but after looking at all the spudger steps to get to the drive and then your comment that the replacement might not actually work... forget about it! I ain't going to all that work for possibly nothing... t'ain't worth it!
Anyone want a perfectly working Xbox 360S with a drive the spins game discs upon ejection? We've already bought a replacement, so this unit is for sale... name your price.