I would be looking for a bad connection between boards or something similar.
Ten pages of posts are not relevant. He, or you, need to talk to JVC and get the real information on the matter. If he is not a JVC ASC that may be difficult, but they should at least be able to refer you to someone who can answer your question definitively.The technician is supposed to come back tonight to look at the issue, I have 10 pages of posts of what can happen if the back is removed while powered on, do you think covering the hole with tape, replacing the back and powering up the tv will reset the dvi?
IIRC there is simply a photodiode that changes a setting in the EEPROM in these (if activated while the set is plugged in), not an old style UV erasable EPROM. Note the difference in the acronym. There is no schematic data on the digital input board, however, so it is hard to be sure exactly what they are doing, but most techs routinely cover it or just don't fire the set up with the back cover open.I remember I read somewhere else that there's an EPROM for this DVI. There's a round optical hole on top of the EPROM. When TV is on and light goes through the hole to EPROM, the EPROM will be ERASED. There used to be a lot of these kind of EPROMs for MCU. JVC will be your last resort to get it programmed or get a pre-programmed part.
What someone really should do is to take off the back cover while TV is powered off, and use something like black electrical tape to cover that hole up before powering up the TV again.