So now that Skype is leaked, I've been messing with video. I'm rooted now, but in #3 above I wasn't. Those problems are still in my way, yet my son's TB works fine.
I've tried the clear data fix. Tried force close, clear data. Tried a reboot. I get about 20-30 seconds of FFC image preview in camera mode, less in camcorder mode, then the image freezes. Sometimes it comes back, sometimes not. Sometimes if I switch to main camera then back again I get a black screen, sometimes I get an image.
In Skype I get a force close eventually, after about 45 seconds of perfect voice and a black screen that should be video between the usual Skype buttons.
I find it hard to believe that this could be a hardware problem, and I'm really reluctant to backing up, unrooting, going into Vz for a replacement, rerooting, and restoring. I would hope there's some other possible way to fix this.
The only video app I ever installed that could potentially cause a problem is the Evo Qik app. I've uninstalled it, because these FFC video problems were happening back in March, like my post above says. I've looked all over to try to find anything Qik might have stored that is specific to an Evo and is causing the HTC camera app to have these problems.
Can anybody throw me a pile of guesses to try? Pleeeez? FWIW, once I post this I'm going to read up on unrooting. I think a replacement TB is going to be the only way. Surprise me.
BTW, I forgot to say that I only installed Qik pre-wipe for root. Anything Qik did, it did in a place that no longer exists.