Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 17"

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darkcrono
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by darkcrono »

it must be video signal -> 33 ohm, 75 ohm to ground,cap, jvc video board.

my problem was somehow fixed after several trial and error, by doing the same, weird, but i have a little banding, i'll try to change sync cap
CLickCLK
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by CLickCLK »

Stra1, darocrono, huge thanks to you. I redid the wiring in correct order and now it works great! Tried my megadrive clone - picture is amazing (also, it worked only without resistor on sync line inside cable). The difference between composite and rgb is simlpy shocking.
Jensan84
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by Jensan84 »

Hi

My first post. :D :D

I have done this mod to my JVC TM-H150cg. But I get a very strange error.

I connected my Sega Mega Drive 2 to my soldered in SCART connector. And picked input D. And I get picture and I can see that all the colours are there Red Green and Blue but I get no white. Everything that should be white is black or appears to be black?

What have I done wrong? Would be super thankful if someone could help me.

// Jens
Sylph4
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by Sylph4 »

Had a sync problem with TM-H1750CG, but going through composite input on the back works perfect!

I wonder now, if it's possible to get component signal working?
skum
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by skum »

The monitors that already accept a card, instead of hacking RGB into them, I would definitely suggest you solder up (or buy) an IF-C01COMG clone instead as you then have signal conditioning and all functionality readily available.
Sylph4
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by Sylph4 »

skum wrote:The monitors that already accept a card, instead of hacking RGB into them, I would definitely suggest you solder up (or buy) an IF-C01COMG clone instead as you then have signal conditioning and all functionality readily available.
It seems, that I do not need it, because I thinked, that through the component connection I can get 480p, but this monitor only supports 15 khz signal
Classicgamer
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by Classicgamer »

Do these monitors really need to be hacked for RGB? This guy is selling replacement input boards for some of the JVC pro CRTs. For example:

https://www.ebay.com/itm/JVC-monitor-SC ... Sw24Ra~UJn

It looks like the rgb input card replaces the NTSC board that comes with the monitor in the pics. Might be worth asking.

I am waiting for an answer about comparability with my Ikegami. Apparently some input cards are compatible with JVC, Panasonic and Ikegami monitors. I have RGB already but I wouldn't mind adding more ports. I can live without the SDI and NTSC cards.
Sylph4
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by Sylph4 »

Classicgamer wrote:Do these monitors really need to be hacked for RGB? This guy is selling replacement input boards for some of the JVC pro CRTs. For example:

https://www.ebay.com/itm/JVC-monitor-SC ... Sw24Ra~UJn
DIY RGB board is cheaper (2-3$)
SuperSpongo
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by SuperSpongo »

Hey guys,

so I've been trying for a while now to get the RGB mod on my H150CG working. Unfortunately, I get horizontal stripes.
I took a video of the symptomes and also measured a couple of signals with a scope:

https://youtu.be/J3ucuN9Kkw4

Quality is not very good, unfortunately :oops: basically, when I move the cursor, there are visible ghosting lines across the screen.

I measured all color signals and Sync. Sync seems to be a little off. I only have a capacitor in the sync line. Should I try other values? Has anybody solved this issue before?

https://imgur.com/a/0sPh0kd
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Star1
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by Star1 »

Any pics of the circuit?
MarkOZLAD
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by MarkOZLAD »

not sure why you would add a cap on the Sync line? I always just pump sync into AV port.

What console are you connecting?
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SuperSpongo
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by SuperSpongo »

Star1 wrote:Any pics of the circuit?
Hi! I used the circuit found in this guide here:

https://imgur.com/gallery/jPoZK

So attenuating the signal first to 0.5Volt, using the 75 Ohm as termination and finally rejecting the DC voltage by a cap in series...
I could upload a picture of my circuit tonight (is there a way to add it to my imgur album? I don't have an account there, so probably not...)
MarkOZLAD wrote:not sure why you would add a cap on the Sync line? I always just pump sync into AV port.

What console are you connecting?
Hi! Like mentioned above, I used the circuit from a guide which showed a cap in the sync line. I did however try to short it and it was no difference.
I'm using a MD1 with CSYNC and also tried a modded N64 with CSYNC.
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Star1
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by Star1 »

You could send sync to the composite input, but then you will have to send a blanking signal to pin 36 (see the other jcm pro guide on the forum). Or potentially, using a cap with a different value could solve your issues. I wrote the original guide, and 10micro has worked for everything I've thrown at it, but I know some other have had to try different values.

Potentially, using the composite input for sync helps with the monitor being picky about sync, but in either case, do check if the sync line one the MD has the required components.
SuperSpongo
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by SuperSpongo »

Hey man!

Unfortunately, I already tested going through a Composite in and using the Blanking pin. I think I'll route out the Sync signal to a breadboard and try different cap values next.
Another thing to try would be to use an Extron Interface and see if the sync processing makes any difference.

Sucks that the mod doesn't work right out of the box, I think I'll have no other choice but to build a whole input card (or just the sync portion of it?).
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Star1
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by Star1 »

It's weird that using the comp input did not work. Did it result in the same issues as when using a 10 microfarad cap on the sync line directly to pin 15?
SuperSpongo
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by SuperSpongo »

Yes it did.
Initially, I had R, G, B and Sync on separate Cinch lines which made it easy to test. Then I thought it might have to do with cable length and shortened everything and soldered the signals to a Scart socket. Now I cannot easily test this again...
Although, come to think of it, I have a Scart Passthrough adapter with breakouts for Composite and Audio. I'll test it again tonight.
SuperSpongo
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by SuperSpongo »

Tried the Composite solution again yesterday. Same behaviour.
skum
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by skum »

SuperSpongo wrote:Tried the Composite solution again yesterday. Same behaviour.
I must admit that I've only worked with this jungle on monitors which didn't have the card option, because the card is so simple to make. but maybe this could be related to the rest of the components for the card already being there? Pure guesswork... I would definitely wire a card up instead of RGB modding it, but in any case it should work just fine. If you are not injecting CSYNC, then you could try making a small LM1881, EL1883 or alike circuit to create it. Are you switching RGB manually or are you using the D button?
SuperSpongo
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by SuperSpongo »

Yeah, I soldered up the path for Sync the other day and used that to rule out that my artefacts come from the faulty sync. The artifacts were still there.
So I'm in the process of soldering R, G and B as well (I already had all the parts at home, except 12V voltage regulator and the 50 pin connector).
Tonight, I'll finish soldering and test again *sigh*.

I'm using the D channel (already soldered a bridge). That reminds me! I'll have to bridge the two pins on my ghetto Input card as well.

I'll post the results later. If it doesn't work, I'll give up and might just sell the two monitors.
CSTV
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by CSTV »

Hi guys,

Brand new to the forum so hello first of all. I bagged myself a JVC TM-H150CG about a month ago and have completed this mod, but i get no picture on the screen at all using a PlayStation 2 with RGB cable, its just a blank screen when I select input D.

I've copied the circuit exactly. RBG wires to 35,34,33 sync on 15 and used GND on PIN 26. I've also connected pin 1 -10 on the CN6005 to trick the monitor into thinking theres the expansion card.

I did have a question about the female RBG connector, do you need to connect all ground pins on it together ? This is the only thing i haven't done.

ImageImage

Thanks in advance for any suggestions.
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Star1
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by Star1 »

Which cable are you using from the ps2? Remember, doing the mod this way requires Csync.
CSTV
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by CSTV »

Star1 wrote:Which cable are you using from the ps2? Remember, doing the mod this way requires Csync.
Im using, what i believe, is a RGB scart. Bought the cable maybe 20 years ago for, I think, my PS1 at the time if I remember correctly. When i plug this scart into the other CRT i have and set the ps2 display settings to RGB, the CRT picks it up and shows RGB on the screen.

EDIT: Ill purchase a csync ps2 cable and see if this works. I guess i could open the plastic sheild and check whats inside my scart cable now, don't think its a csync one though.
SuperSpongo
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by SuperSpongo »

Hi!

I have just tried the mod with your exact monitor type and I can tell you that it will most likely not work. The H150 seems to be a little different compared to other JVCs. You will most likely experience the same picture problems that I had. So if I were you, I'd skip the troubleshooting on the existing mod unless you have an oscilloscope and an understanding of modifying the circuit to behave correctly...

I meant to post a little update, but I'm not quite done yet: I have successfully built an RGB card for my monitor and it works.
skum
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by skum »

SuperSpongo wrote:Hi!

I have just tried the mod with your exact monitor type and I can tell you that it will most likely not work. The H150 seems to be a little different compared to other JVCs. You will most likely experience the same picture problems that I had. So if I were you, I'd skip the troubleshooting on the existing mod unless you have an oscilloscope and an understanding of modifying the circuit to behave correctly...

I meant to post a little update, but I'm not quite done yet: I have successfully built an RGB card for my monitor and it works.
This doesn't make a lot of sense... The thing to deal with is the jungle which is a TA1276AN on a lot of JVCs. I've modded quite a few of these without any issues at all (at least no issues like this), the latest being a TM-A170G which is more or less the same as H150CG (it misses all the circuitry for RGB as it is composite/S-video only). Remove the grounding capacitors (C531-C533), change R554 from 0 ohm to a 10K for proper pull-down, RGB into pins 35,34,33 through the voltage divider (which you can practically skip, and throw 0.7Vpp directly in, terminated with 75Ohm still of course), and then the 0.1uF cap in-line. 5V onto pin 32 (I get it from SCARTs blanking pin), sync into the Input A composite pin, and voila. It took less than an hour to hook everything up, and it worked out of the box. I can't say what is missing in your case, as I always build IF-C01COMG boards for units that support it, but really, it should be a walk in the park... Switching to the RGB input *shouldn't* be necessary unless some specific RGB settings controlled through the OSD, which are only available when actually switched to this input, are needed...
skum
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by skum »

CSTV wrote:Hi guys,

Brand new to the forum so hello first of all. I bagged myself a JVC TM-H150CG about a month ago and have completed this mod, but i get no picture on the screen at all using a PlayStation 2 with RGB cable, its just a blank screen when I select input D.

I've copied the circuit exactly. RBG wires to 35,34,33 sync on 15 and used GND on PIN 26. I've also connected pin 1 -10 on the CN6005 to trick the monitor into thinking theres the expansion card.

I did have a question about the female RBG connector, do you need to connect all ground pins on it together ? This is the only thing i haven't done.

ImageImage

Thanks in advance for any suggestions.
What voltage do you measure on pin 32 when you're in input D? And all the GNDs should be tied together and into the units' GND. Technically only one should be enough, but it depends on how its connected in from the source. What "female RGB connector" are you using? BNC? SCART?
Last edited by skum on Tue Jun 11, 2019 12:42 pm, edited 1 time in total.
SuperSpongo
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by SuperSpongo »

skum wrote:... which is more or less the same as H150CG

Remove the grounding capacitors (C531-C533)...
Unfortunately, it seems do be different enough. For example, according to a service manual I found, the 150CG is missing the grounding capacitors (says OPEN in the manual) and the pads are empty.

I took a couple of pictures with the scope of the sync signal (not sure if I posted those yet) and the sync was messed up.
This might have something to do with the additional circuitry between the 50 pin slot (which supports HV sync) and the jungle chip. Can be seen on page 2-19 and 2-20 of the service manual.
skum
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by skum »

SuperSpongo wrote:
skum wrote:... which is more or less the same as H150CG

Remove the grounding capacitors (C531-C533)...
Unfortunately, it seems do be different enough. For example, according to a service manual I found, the 150CG is missing the grounding capacitors (says OPEN in the manual) and the pads are empty.

I took a couple of pictures with the scope of the sync signal (not sure if I posted those yet) and the sync was messed up.
This might have something to do with the additional circuitry between the 50 pin slot (which supports HV sync) and the jungle chip. Can be seen on page 2-19 and 2-20 of the service manual.
They *should* be missing, because otherwise you'd be "shorting" the video signals to GND. On the A170G and alike, they're put to GND, through a cap, because RGB is not "available" and to leave them floating is bad, and because of the DC offset on the pins, they need to be grounded through a capacitor. You could always try to remove the jumpers or resistors to the left of the pins, and thus completely isolate the RGB inputs from the rest of the system. If the problem is sync, you *could* try to manually switch to RGB (thus staying on input A or B) and inject sync at composite video pin.
SuperSpongo
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by SuperSpongo »

Oh yeah, of course they should be missing, as the cap is (depending on the frequency) a short to ground for AC. I was just using this as an example to show, that the circuitry on monitors with the card option seems to be a little different from the ones without.
CSTV
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by CSTV »

skum wrote:
What voltage do you measure on pin 32 when you're in input D? And all the GNDs should be tied together and into the units' GND. Technically only one should be enough, but it depends on how its connected in from the source. What "female RGB connector" are you using? BNC? SCART?
I'll double check this, I wrote it down ! I'll also check the grounds. I'm using the female scart bought here https://www.retrogamingcables.co.uk/FEM ... -PCB-MOUNT
darkcrono
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Re: Hacking RGB into a jvc TM-H150cg 15" and JVC TM-H1700G 1

Post by darkcrono »

Still having problems with banding in the bright colors mostl, the image

https://imgur.com/ryAgqys

104 cap in the sync line

Any advice?
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