Service Menu for JVC 1997 TV

Post by **The Robman** » Wed Dec 28, 2022 2:31 pm

How did you exit the all green display?

hardtecnica · Post by **hardtecnica** » Wed Dec 28, 2022 3:07 pm

By tapping any button.

hardtecnica · Post by **hardtecnica** » Sat Dec 31, 2022 7:52 pm

So I build up a Irplus profile to try it once and for all. I was in disbelief at the F 255, so I decided to try the non GAPs, one by one until the discrete key called "Brightness". So it pop up:

As soon as I tapped Exit, the settings for the grown-up appears

:

And the so needed VLIN adjustment (TV had a black bar on bottom and incorrect vertical linearity):

For documentation purpose: JVC D3 F109 Back door for Service Menu (tap EXIT then)

And so, after trying all (except the one called "Test Mode

" because it seems to be evil

), my conclusion is that they disabled in the software of the TV the AV Status/Display combo (F106) (maybe for some batches it work). To be sure, even inside Service Menu this code (F106) do nothing, as it should open another menu that I have no interest called SYSTEM CONSTANT. Why they did it, I can only guess they where afraid of customers inadvertently getting into service. Such a shame even with the original remote it wouldn't work.

Post by **The Robman** » Sat Dec 31, 2022 8:40 pm

It looks like you got to the menu that you needed to get to and you were able to fix what needed fixing, right? The trick is to send OBC 255 followed by EXIT?

hardtecnica · Post by **hardtecnica** » Sat Dec 31, 2022 11:27 pm

Yes, I finally got what I wanted. No, OBC 255 was just the last candidate from 256 possibilities. What I mean is that I've tried it all and there's no service menu key as specified on the Service Manual (unless for my unit even if I had the original remote from the previous owner). But I managed to get into there by the already known, but untested till today: OBC 109 ("Brightness", which I call a back door for service menu). Yeah, just Exit after it to get back to the main hidden menu page, as this key is a shortcut for BRIGHT setting there. They at some point locked the OBC 106 for this set in Brazil and I can't get it.

Post by **The Robman** » Sun Jan 01, 2023 8:45 am

Ah good, then I'm glad I sought clarification.

BRIGHTNESS (OBC 109), followed by EXIT (OBC 230), gets you to the Service Menu

hardtecnica · Post by **hardtecnica** » Sun Jan 01, 2023 10:23 am

Joyful moment. I only blame myself for not trying that code sooner. As EXIT is not a discrete key, remote could be used from there.