I've tried everything I can think of ,searched sites & forums, but can't find the problem. The keys & the keybed look identical where the keys are fine & the 2 that pop out when pushed. I've done my own repairs for many years on all kinds of keyboards ,generally quite successfully (an aside- the black key guide caps I glued in several years ago have given me no further problems. I had another one fall off about a year ago, & glued that one successfully also.) but I'm offically stumped. The nearest factory service place is an hour away- & they're talking 10 -20 days turn around time - but them's the breaks