Service Menu for JVC 1997 TV

[hardtecnica]

Could someone please, learn the VIDEO STATUS and DISPLAY pressed simultaneously and share the update file with this code included? I think it's not possible from an UEI remote, just the original JVC or JVC OEM ones, but I'm not expert. My replica can't do it, JVC used ones are impossible to find where I live.

According to the service manual of this JVC AV-T2977, I should while the TV is on, just press simultaneously VIDEO STATUS (Function 13, also know as AV STATUS) and DISPLAY (Function 4) and bang! Service Menu would appear.

What I already tried:

Example of file compatible, except for the service menu part:

https://www.hifi-remote.com/forums/dload ... le_id=1372

I found here some gold .rmdu files that works fine with my TV. In the file above for example, I found three Service Menu codes, one of them is learned from simultaneous press of PICTURE MODE and DISPLAY from an "OEM JVC remote" (F 106). I though it would work with my TV, but didn't, I also tried the other two service menu codes (F 96 and 102) but no luck. So I "scrutinized" why the first one didn't, and I figure out that PICTURE MODE is different from AV/VIDEO STATUS, because it do nothing on my TV, but the other two, DISPLAY (also known as DISPLAY/BACK) and AV/STATUS work as a charm, so there's another JVC service menu code still to be learned and shared.

I also tried many other ways described on internet, as for example, set time to 3:21AM and prompt Mute when "Thank you" display.
I'm asking here because I searched through all the txt and rmdu JVC files here and many searches on the internet, just found here, sadly none of them are for my set.

I'm not an JP1 user (where I live UEI remotes are not available), but as my post was more related to request, I posted here (moderator may move it if it don't belong here).

How I tested it:

I exported from RMIR program to Girr format, from IRScrutinizer program imported to "Scrutinize remote" tab, and so I set manually the "D" to 3 for some buttons wanted that are Device 3 on RMIR, then I exported to wave individually (I had to set repeats to 3) and then to some portable audio player with 3.5mm DIY 2LED IR blaster. IRPlus Wave app would be better and should work also, when I learn how to make every code exported from IRS repeats 3 times in there.

[The Robman]

When you need to press two buttons simultaneously to access a service menu, etc the OEM remote is usually specially programmed to send a different function code when that happens. This is why, why you use a 3rd party or universal remote, pressing the same 2 buttons together doesn't work.

The secret service menu codes usually (but not always) come from the same code set as the main button codes. As you have a way to test codes using your IR blaster, I would suggest that you try all of the "gap" codes (ie, OBCs that are not already accounted for) from that upgrade file.

[hardtecnica]

Indeed! It's like an extra button. I think they did this way (two keys) to force only their product could open it, no reasonable reason for this.

By "gap" codes you mean that I should for example, in IRScrutinized, under scrutinized remote tab add empty signals and manually try all the OBCs(F) unlisted, for example, 108, 110, 111 etc? (Yes, I'm a bit scared of trying, for example, there's the 107 that is "Test mode"(!?), the rest will mostly have no function but some of these who knows? (Scary, scary thing ).

[The Robman]

Yes, I do mean test any codes for which the purpose has not already been identified. The valid OBCs are in the range 0-255. What we normally do is, copy/paste all the known functions and their OBCs into a spreadsheet and then have the spreadsheet figure out the gaps. Then we paste those into dummy upgrades and test them using our JP1 remotes. In your case, you would just need to enter the gap OBCs into IRScrutinizer.

I do notice that your upgrade uses 3 device codes (ie, 3, 0 and 35). I expect you to have the best luck testing using device code 3 as that's where most of the functions are to be found, but there are 13 functions from device 35 and one from dev 0.

[hardtecnica]

Yes, D3 should be my best chance. Before trying the gaps, there's an untested method for the menu service I should try before, still with the F 106. The author of this upgrade states that it was learned from "video status and display" in the link below:

https://www.hifi-remote.com/forums/viewt ... 9a6ca3c874

But in file notes as "picture mode and display" where the first is a different key. But maybe it doesn't matter and the combo send the same code anyway. The method I found on a TV repair page for my exactly model differs from what is described in Brazilian service manual (my TV is from Brasil). This repair site states that "TV should be in stand by and then video status and display should be hold for 15s (I think this time is exaggerated) and then power." I did some tests before but not holding it, just the combo and power on. I already tried simulating a long press following this picture below but no luck, (I did time before a wave editing captured from zaza app like that image for Toshiba TV that worked, even before knowing about it. That model generated the pulse and burst at the end of the command which facilitated to observe and try repeating just that indefinitely) for JVC maybe the long press is represented other way. I tested mostly with VOL+ to see if it would hold, don't. Repeating the code indefinitely does hold VOL+ but I'm sure it's just like tapping the button, not holding it. For sure I'm missing something to simulate the long press here.

NEC protocol long press: https://imgur.com/TcyNC24[/b]

[The Robman]

That old thread does confirm that VIDEO STATUS and DISPLAY pressed simultaneously yield OBC 106, so that is no longer a mystery. If the instructions say to hold the buttons for 15 seconds, then that might be the part that you're missing, if your IR-LED method isn't doing that.

[Barf]

By "gap" codes you mean that I should for example, in IRScrutinized, under scrutinized remote tab add empty signals and manually try all the OBCs(F) unlisted, for example, 108, 110, 111 etc?

In the Scrutinize Remote/Parametric Remote table, you can just select one line, press the right mouse button, and select Advanced -> Add missing Fs, and all the "gap" signals will be generated, with dummy names.

(Yes, I'm a bit scared of trying, for example, there's the 107 that is "Test mode"(!?), the rest will mostly have no function but some of these who knows? (Scary, scary thing ).

IMHO, there is a small but real risk of putting the device in nasty state. (This is my own experience with a Panasonic player.) I always write the following disclaimer in IrScrutinizer/IrpTransmogrifier (mainly to protect myself):

Warning: Sending undocumented IR commands to your equipment may damage or even destroy it. By using this program, you agree to take the responsibility for possible damages yourself, and not to hold the author responsible.

If you have suitable IR-sending hardware connected to the computer, you can also send the IR command candidate directy from the Scrutinize remote table: just right mouse button and select "Transmit selected". I.e., no need to transfer it to a JP1 remote first.

[hardtecnica]

If the instructions say to hold the buttons for 15 seconds, then that might be the part that you're missing, if your IR-LED method isn't doing that.

Thank you for the tips so far.

Yeah, I'm struggling with that right now. It's possible to simulate it by simple wave editing if I knew how in JVC protocol long press command behaves. Probably there are some elegant way to do that I still don't know. Any tip is welcome.

[hardtecnica]

Warning: Sending undocumented IR commands...

Thank you for the tips, very useful. Yeah, I saw your warning before, that's the main reason I will not try it now, as you can read above, probably I already found the OBC I need, I just need the long press thing sorted out.

[The Robman]

Yeah, I'm struggling with that right now. It's possible to simulate it by simple wave editing if I knew how in JVC protocol long press command behaves. Probably there are some elegant way to do that I still don't know. Any tip is welcome.

Here's the spec on JVC:
http://www.hifi-remote.com/johnsfine/DecodeIR.html#JVC

Basically, the lead-in pair doesn't repeat, but the rest of the signal does.

[hardtecnica]

Basically, the lead-in pair doesn't repeat, but the rest of the signal does.

Indeed! Is what I found here:

https://www.sbprojects.net/knowledge/ir/jvc.php

Which is exactly what repeats do in IRS. So I tried it again just to make sure and even with 15s, also holding with TV turned on, also tried with F 96 and 102 and no luck. So I will stick with the Service Manual information, since that should be the only reliable source (that site is not a forum, so there's no discussion about someone using that method, just a shared info by someone that besides being stated for my model, potentially is incorrect). Seems it's not F 106 after all.

Add missing Fs from Barf is gold, it will help me in the next endeavor (but I'm still afraid, I will do some more deep research before it).

[The Robman]

Because you're using a homemade setup to send these signals, my recommendation would be to do a POC to verify that it works, before deciding that OBC 106 is incorrect. I would recommend that you do the same setup for the volume+ button and then see if, when you send it, the volume increases for 15 seconds. I would also recommend not having something playing on the TV at the time!

[hardtecnica]

Yes, all my test is based on VOL pressed first, and seeing if it works. I only test the service menu key after testing the basic buttons before. Nothing is playing, just blank AV input.

I also tested my setup from files from here with others TVs of mine like LCD and for example my 10" Toshiba CRT (here under the brand SEMP) that need mute pressed for some seconds to enter service menu, and it worked just fine. (I found IRScrutinizer to be perfect on simulate a key being pressed under repeats option ).

The only thing that I notice specific with my JVC is that any key only works if it's repeated at least 3 times from IRS (the others I can leave on default 1), I can repeat to 100 and even higher through audio editing and it will work like a key is being pressed (since from IRS the lead in send only on the first code for JVC Protocol like it should be). Signal is strong so the code is being send, but somehow TV rejects the 106 as being SM. I already found in Remote Central website that the code is F106 for another JVC TV that his service manual states the same combo and way as mine and it drives me crazy. My theory is that my Brazilian model his remote share the same keys, except for Service Menu code, using the same combo as the north American but sending other code (it doesn't make much sense and my TV could be "defective" because 106 definitely should work ).

It's made by Gradiente, model HT-M299S, but it's actually a JVC AV-T2977 which was also marketed in Brazil and Mexico. Service manual is from Gradiente.

[The Robman]

Then you just need to decide if you're brave enough to test the gap codes. If I were you, I'd do it, but of course it's your decision.

There are some interesting looking gap codes in the low OBC range, but if they do anything I'd expect them to most likely be normal functions. My money would be on an OBC in the low 100s, but I'd test all of them.

Here are some of the gaps that I'm seeing:

1,2,7,8,9,12,15,21,22,27
42-59
61,62,63,64,67,68,70
72-89
92-101 (skipping 96)
103,106,108
110-115, 117, 118, 120

[hardtecnica]

So far I tested 92-101 (did nothing). 103, 106 and then... 108 and my heart almost stopped, all green display.

For documentation purpose: JVC D3 F108 Green signal.

When I'm braver after that maybe I'll go ahead.