power issue - phone won't stay on, even with multiple batteries

[FearTheElf]

Here's my sob story:

A few days ago my phone all of a sudden went completely dead (never had any issues with it before, been running an updated ROM with Windows Mobile 6.1 for a year or so, no other recent updates). I plugged the phone in to the AC charger and all I got was the solid red light. The phone started booting up, got into the Windows Mobile startup process, then completely shut off. After that, the phone would not turn on at all, not even the red light appeared when plugged in. I was convinced that the battery was toast, so I ordered a couple new ones. (By the way, I have only ever used the AC charger that came with the phone, however I have used multiple USB cables to sync with different PCs)


This is where it gets nutty. I installed one of the new batteries, and it powered on just fine, and worked. Battery was low, so I plugged it in to the charger. About 30 minutes later, it shut off again. No light, wouldn't power on. So I tried the other new battery. Got the solid red light when plugged in, but no activity. Then I tried removing the battery while plugged in then reinstalling the battery (per a tip I found searching on here). Only got the solid red light for awhile, then nothing. Awhile later, it actually turned on and worked fine for a couple of hours. Then shut off by itself. Then turned on fine for about an hour. Then shut off by itself. Then turned on fine for about 30 minutes. Then shut off by istelf. Then started booting up and shut off, not coming back on. Plugged it in, got the solid red light for awhile, then nothing. Tried removing battery while plugged in, got a FLASHING red light this time... put the battery back in, no light. Then flashing red again. Also tried switching batteries again. Had the normal yellow charging light for a second, then back to flashing red. Then solid red. Now nothing.

Any tips, or should I throw it in a lake?