Vince,
Thank you for that suggestion. I had come to that conclusion myself and was arranging to either buy the part or cannibalize one from another MacBook I'd given to an IT friend for parts (he never used since he's a PC guy).
Before doing that, I took your advice and did one more check with an AC adapter at a store and it actually worked! Of course, when I got home, neither of my adapters worked so I figured your were right and they both suddenly failed.
Sometime back, I'd found a brand new AC adapter on clearance for $20 and purchased it as a spare for my dad. He never opened it so, in another example of backsies, asked if I could relieve him of it. Went to get it yesterday and brought my current one along to test on his computer. The new one worked perfectly and, lo and behold, so did my old one. I've got them both now but I'm still using the original one while the new one is in ready reserve.
I don't know why.
My weird guess is that the new one (not the service adapter at the store) had some combination of perfectly clean contacts (mind you, I still have the plastic cap on mine and always use it) and lowest resistance so that the power supplied was optimal and it somehow got past some issue which fixed the glitch for all. My oldest AC adapter still failed so I discarded it. I don't know how long the current adapter will work and don't know if the board is still an issue waiting to completely fail but hopefully I'll get that parts computer before I need it.
Thanks!
