Don't believe you are alone. JVC must have pissed off lots of customers with that one. As far as I am concerned, I used to like the make for well manufactured products I used to buy from them in the nineties, but I will never EVER buy JVC again after that disastrous experience with the GR-DVM90U.
Mine suffers same symptom as your's and lots of others. JVC never stood behind that product and never offered a recall. They preferred handling it on a per case basis, to save money, hoping that only a few people would care enough about their grand of investment to complain. Very bad, short sighted, idiotic customer support management if you ask me! They have so many disgruntled customers out there now, ready to jump and give them the negative publicity they deserve, they will loose much more in the worsened image of the firm than they'd have in straight cash if they had pulled their acts together and replaced the faulty devices.