JVC TM-H and DT-V thread

[serbusfish]

I'm thinking now that the bar type setting only shows up when there's an SDI input active. I've put away my SDI card as I never have a use for it, but it's probably for something SDI-specific, but if it does refer to that bar at the top it may affect all picture modes after you change it.

On my two monitors with RGB lines I don't really see the glow, but they could be higher in the vertical overscan area than yours. I'd try increasing the vertical size to see if that makes a difference.

Unfortunately messing with overscan makes too much of the image go off screen. If I could obtain an SDI input card how would I go about getting a signal into it? I have no experience with SDI at all.

Hi all,

I have a JVC DT-V1700CG, and I cannot get my RGB consoles to display. Unlike the 1710CG, the 1700 only has automatic sync detection, and there is no option to switch to internal sync in any of the 3 service menus.

If you're using RGB you will need to use external sync not internal. Interal sync is for component input, if you have RGB you'll also have a sync cable, usually yellow?

[GuardinojoeATL]

If you're using RGB you will need to use external sync not internal. Interal sync is for component input, if you have RGB you'll also have a sync cable, usually yellow?

I am using an RGB SCART cable with C-sync, so it has "external" sync built into the cable.

That really isn't the issue I flagged in my post - the monitor is naturally set to internal sync, and has no menu option to switch to external sync, so I am looking for a way to force that change through otherwise.

The monitor's counterpart, the DT-V1710CG, DOES have a menu option to switch to external sync.

My monitor uses "automatic" detection that apparently does not work for internal sync RGB. Any help or ideas would be appreciated

Thank you!

[famiac]

@fernan1234 Hey, I was testing out one of my JVC DT-V1710CG's that I want to sell, and I can confirm that on this unit underscan and aspect buttons do work with RGB.
This is my most recent unit manufactured in february 2008. On my second DT-V1710CG (2006) and my DT-V1910CG (2007) those options are blocked for RGB.
There is definetly a way to enable them, but still I have no idea how to do it.

@Namingway_PL
There's either a difference in the CPU code or in the FPGA code.
Could you check the CPU program version on your 2008 DT-V?
it should be displayed after you select "UPDATE CPU PROGRAM" from page 2 of the service menu.

It is possible to dump the program from the MCU via RS-232C and write it to your older monitors.
(I'm using the words CPU and MCU interchangeably here...)

[Namingway_PL]

@famiac Unfortunately I can't, because I don't own this unit anymore. It's really not a big deal. I was just curious why do they behave differently, and if this was due to different software or maybe some settings in the CPU block.

[fernan1234]

I still have both a unit that that can change scan and aspect with RGB and one that can't, so I'll compare the CPU program versions and post them here when I get a chance to dig out one of them.

What would be the easiest way to dump the program and then to flash it to the other monitor?

[serbusfish]

My DT-V1710CG only has 1 slot used with an aftermarket BNC RGB card, the other two slots are empty. Am I right in saying I could purchased two more of these cards so the monitor will have 3x BNC RGB inputs?

[Namingway_PL]

@serbusfish Yes, You are right. With three cards You get three RGB or YpPbPr inputs. But You also can just get a matrix switcher like a extron crosspoint and have many more inputs

[famiac]

What would be the easiest way to dump the program and then to flash it to the other monitor?

you need a USB to serial port cable and a laptop. you'll also need a custom circuit board that is fairly easy to assemble. i'll make the design public in a couple days or so.
the annoying part is that you have to make a slight modification to the CPU board itself, but it's only one trace cut and one wire.

[lewolfeur]

Hello, It's been a while since I've been on the forum.
I have one of my 1900 who is stored, from december 2002 and only 3k hours.
But now when i tested it he have an issue ,when display image with intensity ? (never really used it since i buyed it maybe he already had this issue because there is x6 ray issue in diag of service menu)
Check the video, when image change it seem image appair, the image seem bigger when signal is white ? also see it on storm in zelda at end of the video.
https://www.youtube.com/watch?v=pt2vgXPwfoE

What may be the issue ? in service manual for x-ray say to check ic801 from pwb and ic503 from hv signal.


Also my main 1900 from february 2002 with 46k also start to have a small issue with the image enlarging a few minutes after turned it on, then shrinking and enlarging again in a random way..There is a good chance that this is due to a capacitor
visible in video at 1:04 https://www.youtube.com/watch?v=iHIB2bCozKs

Has anyone ever had one of these problems?

[Tafty]

Hi Guys,

long time lurker, first time poster. this thread is one of the main reasons i got my DT-V1710cg so cheers


does anyone here use one with mister and has 240p/480i AND 480p setup? basically in short I have direct video working via a hdmi to vga dac, this works perfectly for the cores that support it, BUT was hoping i can use an alt ini for 480p mode..but i cant seem to get this working correctly...does anyone have something similar setup?

[fernan1234]

Check the video, when image change it seem image appair, the image seem bigger when signal is white ? also see it on storm in zelda at end of the video.

This is pretty much always from video levels from your RGB cable being too high. Is it some old SCART cable? Nowadays cables from good cable makers avoid these problems.

Also my main 1900 from february 2002 with 46k also start to have a small issue with the image enlarging a few minutes after turned it on, then shrinking and enlarging again in a random way..There is a good chance that this is due to a capacitor

This kind of intermittent issue on the other hand is indeed most likely due to caps that need replacing, especially if the behavior changes after the monitor has warmed up for a while.

[lewolfeur]

its the official cable for snes, he also work without issue on another monitor like 1710 or 20f1.
Tested it on my second 1900, the one with 46k and there no problem with rgb level.
Maybe, i will try to use another rgb card and also another console.

But for me, its from the monitor.
So for you is something like a overload led on bvm from too hight signal ?

For the 46k i need to identify where the deflection cap are and replace it, or better replace all from main board ?

Edit 07/03
same with other console, calble.
And now each time i start it this happen.
https://www.youtube.com/watch?v=9c4RYHlg1Qw
Maybe there a issue with flyback ? lower the screen on the flyback ?

[famiac]

@lewolfleur does your monitor shut down when you press the degauss button?
I would also consider replacing capacitors. probably all of them on the main pwb.

has anybody had purity issues with the DT-V's? one of mine has a blue spot in the bottom right corner.

EDIT: after almost a whole day of messing with the purity rings, i've found a setting that eliminated the issue and maintains convergence.

[fernan1234]

And now each time i start it this happen.
https://www.youtube.com/watch?v=9c4RYHlg1Qw
Maybe there a issue with flyback ? lower the screen on the flyback ?

That's input D blinking right? According to the service manual:

INPUT D blinking at 0.5-second intervals
X-RAY
X-rays detected
• SIGNAL PWB ASS'Y IC801
• HV CONTROL MODULE PWB ASS'Y IC503

Those two boards/ICs would have the malfunctioning circuit. I've heard about ICs going bad on these monitors before, though they should be replaceable. I wonder if running the self-diagnosis test in the service menu might help.

Looks like you have a nice unit with low hours and the anti-glare film intact, hopefully you can fix it! BTW I'm curious about people's care approach for keeping the screen clean. I only let a soft and dry t-shirt touch mine. Seems like even a bit of water followed by rubbing can strip the paint off the film on some of these.

has anybody had purity issues with the DT-V's? one of mine has a blue spot in the bottom right corner.

I've seen it in a couple of other people's units, and IIRC one had it on the bottom right too. I'd try changing the direction the tube faces to see if that makes a difference. Sometimes adjusting rotation, either the digital setting or the pot inside the monitor, can help with purity issues. Too bad these don't have the nice purity digital adjustments that some of the later BVMs had. Last resort would be playing with the purity rings I suppose.

[famiac]

the slightest bit of force will take the finish off the screen. i speak from experience T.T
I use only a dry cloth as well from now on.

IC801 is the MCU. if you want to dump the code from your working monitor and try flashing it to your non-working one, here is the PCB i was talking about:
https://github.com/famicomical/MB9X-UART

the github repo should have all the information you need to build it, including a guide to modify the DT-V monitors for reprogramming.

[kitor]

And now each time i start it this happen.
Those two boards/ICs would have the malfunctioning circuit. I've heard about ICs going bad on these monitors before, though they should be replaceable. I wonder if running the self-diagnosis test in the service menu might help.

I would check the board for any obvious cold joints. A few months ago I scored TM-H1950CG that was not turning on, it had a cold joint in x-ray detection circuit. It turned out to have just 200h and a pristine CRT.

[famiac]

just wanted to post the drill pattern i made to re-use an I/O slot cover with the 3rd party RGB/Component cards.
This was designed to accommodate the boards by Martin Hejnfelt.



You can also drill the PCB to use it with the LC31465 shield.

Finally, no more rattling when you move your cables!

[coderkind]

Does anyone know if the official JVC IF-C01COMG cards accept TTL-level sync (e.g. from an Extron Crosspoint)? I've been advised not to use it with clone cards, and the manual for the TM-H suggests it only accepts 75ohm sync (I think).

I'm currently attenuating the sync levels from the Extron via a BNC-to-SCART adapter with a resistor in it; it'd be nice to not have to use it.

[fernan1234]

Does anyone know if the official JVC IF-C01COMG cards accept TTL-level sync (e.g. from an Extron Crosspoint)? I've been advised not to use it with clone cards, and the manual for the TM-H suggests it only accepts 75ohm sync (I think).

I'm currently attenuating the sync levels from the Extron via a BNC-to-SCART adapter with a resistor in it; it'd be nice to not have to use it.

Yes you can use TTL sync with the original card. The TM-Hs also work totally fine with TTL, maybe you're thinking of the composite video input.

[coderkind]

Yes you can use TTL sync with the original card. The TM-Hs also work totally fine with TTL, maybe you're thinking of the composite video input.

Yep; I can see that for the composite video input (VIDEO A/B https://www.manualslib.com/manual/81898 ... =11#manual), but can't see anything for the input card slot.

The reseller for the replica component input card advised not to use TTL sync with it, so I'm wondering what usually deals with the sync here; the card, or the monitor?

[fernan1234]

Yes you can use TTL sync with the original card. The TM-Hs also work totally fine with TTL, maybe you're thinking of the composite video input.

Yep; I can see that for the composite video input (VIDEO A/B https://www.manualslib.com/manual/81898 ... =11#manual), but can't see anything for the input card slot.

The reseller for the replica component input card advised not to use TTL sync with it, so I'm wondering what usually deals with the sync here; the card, or the monitor?

Monitor has no problems with it. Not sure about the clone cards as I don't use them, but if it's one with SCART input it would make sense for it to advise 75ohm, and if the BNC version is identical except for the connectors then that would explain why it's 75ohm only. Again, you'll have no issues with the original card and TTL.

[atohmdiy]

Hello,
With my TM-H1900G i still have this sync wobbling. It's usually one line that is wobbling, and it appear with the menu too. I mod the monitor for RGB. Sync is unchanged, i just plug my composite sync to the Composite A channel BNC. I take care of the level, composite is 1v and my sync is TTL for i use a cable with a resistor.

https://www.youtube.com/shorts/BO7_P676nuo

[fernan1234]

Could you check the CPU program version on your 2008 DT-V?

Finally got a chance to compare both monitors.

The DT-V1710 that can change aspect/underscan for RGB inputs indeed shows a newer CPU Program ver. 6.04 (EEPROM version shows 005, FPGA version 102). The 1910 that can't has CPU Program ver. 5.06 (EEPROM 216, FPGA 060).

How does this match up with the versions you've seen in your research?

I also noticed that some of the values within the SET FPGA menu are different. Always had hopes that changing some of these would be enough to enable those picture functions with RGB, but it's probably not that easy.

[coderkind]

Hello,
With my TM-H1900G i still have this sync wobbling. It's usually one line that is wobbling, and it appear with the menu too. I mod the monitor for RGB. Sync is unchanged, i just plug my composite sync to the Composite A channel BNC. I take care of the level, composite is 1v and my sync is TTL for i use a cable with a resistor.

https://www.youtube.com/shorts/BO7_P676nuo

I get this with certain MiSTer cores (e.g. the new IREM M92 one), especially at the top. I've tried an Extron RGB 580i to regulate the sync, and while it improved it a bit, using the device also seemed to dull the picture.

I'm sure sure if there's a "best" device to use with a TM-H to sort this? Extron RGB 203? 160?

[lewolfeur]

i have to recap my 1900, I search a part list pdf for 1900 but not find it :/
anyone already made a capkit list or partial of some board ? (maybe from a 1910)

I don't know if some of the components are also the same on the 1710, if so, if someone has a list I'm also interested

[feded]

Hello, I'have a TM-H150cg with dim picture. If I try to turn up contrast and brightness the image presents streaking lines. Is that a symptom of a weak crt or could be caused by bad caps? Does anybody experience something like this?

[famiac]

wanted to share this simple circuit you can use to dramatically increase the sync compatiblity of your DT-V monitor.
Building the circuit into your RGB card will allow you to use 75 ohm composite video or c-sync as your sync signal without the need of an extron box to shift the voltage levels to TTL.



it's just an LM1881 with level-shifting.
Here's a photo of it installed:



after modding your card, your DT-V will still be compatible with everything you have hooked up already but the need for an external sync processor will be eliminated in most cases.

[DejahThoris]

Check the video, when image change it seem image appair, the image seem bigger when signal is white ? also see it on storm in zelda at end of the video.

This is pretty much always from video levels from your RGB cable being too high. Is it some old SCART cable? Nowadays cables from good cable makers avoid these problems.

This is also how monitors act when the filter caps are getting too out of spec.

[DejahThoris]

wanted to share this simple circuit you can use to dramatically increase the sync compatiblity of your DT-V monitor.
Building the circuit into your RGB card will allow you to use 75 ohm composite video or c-sync as your sync signal without the need of an extron box to shift the voltage levels to TTL.



it's just an LM1881 with level-shifting.
Here's a photo of it installed:



after modding your card, your DT-V will still be compatible with everything you have hooked up already but the need for an external sync processor will be eliminated in most cases.

Do you reckon something similar could be done with the non-V models? I've got a DT-2730 I've been just this week looking for an external sync processor for to solve the very problem this solves.

And if not, any suggestion on a particular Extron box?

[famiac]

i'm not sure what voltage levels that monitor is expecting, so i can't recommend the exact circuit i shared for your monitor. does it have the same RGB input card?