sup guys... I've got an Alltel TP (should be same exact as Sprint inside). I bought it under the impression the KB goes out now n then (after I lost my Sprint version), but after bringin it home, it stopped completely. the KB will lite up, n make sliding sound but no resp. to key strokes....
so, after reading the posts, decided to disassemble it before goin to ebay n buyn a new KB for $40. after detaching the 2 ribbon cables, and using a can of air to clean, pushed them back in place firmly and checked for other loose end under the KB. I plugged it in to test (while still apart) but no luck. so I took the battery out (that did a reset) and put the phone back together and after it came back on, started to work 100%!!!!!!
so, might be worth givin it a try before buyn new KB (if out of warranty like mine).... good luck.