Phone won't start
Caveat - This is my son's phone, and only the recent observations are my own. I can't be sure he didn't do something to munge it up, though I am fairly certain he has not tried to flash it (I haven't either). In any case . . .
I bought an unlocked SMT5600 on eBay about 6 weeks ago. It worked great for about 3 weeks, then went on the fritz. It started by only booting to the red-green-blue OS screen. Removing the battery did nothing to reset it. It was still doing this when I retrieved it from my son. When I finally had time to look at it four days later, it booted once or twice to that screen, but then stopped doing even that. I have since done research online and not seen a similar situation. Other observations - there is no change if I swap out the battery for one that I know is charged. After replacing the battery, when I insert the charge cord (wall plug, not USB to PC) the power light flashes red briefly, then goes black and never comes on again.
Of course the eBay seller is telling me I'm SOL at this point. Before the problems began, I actually bought three more of these phones from the same seller and none has had any problems. My son is not into modding or installing programs, and tells me he has done neither. I think this is likely the case, but it is conceivable he or a friend might have tried something. So I am looking for assistance/direction in what to try next. Although I don't think I have the correct torx to disassemble it right now, I am willing to get the right tools and give that a go to avoid a $150 paperweight.