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

[soviet9922]

This is my first post, so i like to say hello first guys i have seen that here is the only place on the net where i see people doing some TV hacking and monitors read the threads and learn a lot.

I have some experience hacking RGB into tvs, already done a Panasonic 32" tv and got a very good image, also have some experience in electronics and studied TV and electronics when i was young.

Then lucky me scored 4 JVC monitors x3 tm-h150cg 15" and x1 h1700 17" also a sony, none of them have RGB on them so...


When i found this guide http://imgur.com/gallery/jPoZK about hacking RGB into this monitors i think is going to be pice of cake.
Started by one of the h150cg to keep it simple follow this guide step by step do the same schematic for the color lines and added a ceramic 104 cap 0.1 in the sync line, the only difference is that i used 33 ohm resistors in place of 30 ohm. The caps in the color lines are also 0.1 104 ceramic.
Added the wire from pin 1 gnd to pin 12 on the connector to trick the monitor into RGB, and choose the input D on the front panel.
pictures:


OK so i hooked up my genesis (modified to output pure sync on RGB scart) and got this banding on the bright parts of the image.
So that was bad so tried my MSX2 computer and have the same issue, then tried using my PS2 and PSX and have the same problem.
pictures:


Not sure why i get this banding if it is a sync issue or how can i fix it ?.
I was unable to find the schematic for this monitor or the data sheet for the Jungle IC if somebody now where to find it ?.
If this monitor have a service mode to center the screen and adjust the size ?.

Thanks!.

[soviet9922]

Figured out a couple of things:

First the jungla IC is a TA1276AN, in the article cited in the start of the thread the name is wrong i was unable to find it for that reason.
link to the pdf here: http://www.filehosting.org/file/details ... 1276an.pdf

Also change the capacitor on the sync line from the 104 to a 473 (0.047uF).
This got the picture perfect and stable , so the cap value was the culprit.


OK things are looking great on this systems using RGBS all scart cables.
Genesis picture looks great.
32x picture look great.
PS2 picture looks great.
PSX picture looks great.
MSX2 computer look great.
Original xbox looks great.

But but but but but but (jeff goldblum mode)
My atari ste sync looks very bad but why ?, tried different caps values and added resistors but this only get this issue worse. So tried an LM1881 sync striper to clean the sync signal but this don't worked to fix the sync on the ste and in any other system mmm.

OK from my previous experience (hacking RGB into my panasonic tv) found that was easier to hook the sync signal to the composite input in place to the sync pin on the jungla to use the internal sync circuit separator in the TV.
In this case the monitor switch to RGB when i select input D on the front panel this disable the composite video input so i have to find a way to force the monitor to the RGB jungla pins (33,34,35) when is in input a or b (composite inputs)

So decided to try this on the monitor, looking at the jungla datasheet found that pin 32/YS2 change to the RGB inputs when you have +0.75V on it.

Started to poke arround the jungla ic to find a proper voltage and found 0.8+ on the a small resistor that is very close to the top of the IC (will add pictures later).

OK, now hooked up a wire from pin 32/YS2 to this resistor, then soldered a wire from the scart plug sync line straight to the composite video input on the monitor.
Have to use input B for this input A don't seem to work.
So on the front panel when i have selected input B i have RGB anyways and the sync works fine using the composite signal, my Atari ST looks fine and dandy .

Have to clean up and install the pcb inside the monitor chassis will fix up the schematic and add it having my modifications.

[Star1]

Great work man!
I made the original guide, never thought to trick the jungle ic to accept sync via input A/B.

If you need the service manual, just send me your mail adress in a pm, and I'll mail it. There is a set of button combos needed to access the service menu, and each setting is just listed as for example D1 rather than what it does, so it is needed unless you want to spend a lot of time.

Edit: Weird that you needed a different cap value for the sync line. Also interesting that using a sync stripper didn't work, I had the same experience, although I just tested that on the Saturn if I remember correctly.

[soviet9922]

Do you are the author of the article!, thank you very much for it is very clear and help me a lot.
So the service menu is no easy to use, but i have to adjust the position of the screen so i have to go in have no choice, PMed you my email address.

The different cap maybe is because i used a different system for testing i see you used snes maybe on the snes the 104 value cap is fine, but not on the genesis but if you tested o a Saturn also. I have ordered a saturn and scart cable from japan so i can confirm that latter.

Decided to add a 3 pole switch on the back to choose sync to jungla o sync to composite and force the blank signal at the same time and have the option build in the monitor.

Going to do the 17" model now i almost finished.

[Star1]

I tested all my systems, Nesrgb, snes, mega drive, saturn, ps1, n64, dreamcast, they all sync fine with 104 cap.

Is that the 17" without the option for the input board?

[soviet9922]

So the problem must be in other place maybe is the caps that i used.
Yes indeed is the 17" without the option boards.

[Star1]

Cool, post pics when you are done

[soviet9922]

Ok finished it, added the audio output nothing fancy just rca plugs using shilded cable to the scart socket.
Also added a DPDT switch that choose sending sync to the composite plug or to the sync pin in the jungla also at the same time it enables YC2 when it feeds sync to the composite input.
Cable colors are red green blue (they are rgb) brown is yc2 (blanking) from the small resistor to the pin) and (yellow is the sync line) black is ground from exp connector and the red wire in the exp connector is the expansion card detection enable.

[soviet9922]

OK now the TM-H1700G turn, disassembled the chassis and the board look identical to the 150cg, but all components related to RGB options and exp connectors where removed, so the only way is the YS2 force rute.



Should be easy now.

[schadenfreude]

I'm liking the shot of the alcohol for a job well done.

[soviet9922]

More like 2 liters of beer

I'm liking the shot of the alcohol for a job well done.

[Star1]

Nice pics, well done!

[soviet9922]

Hacking RGB onto the H1700G is more or less the same, the only difference is that is required is connecting the YS2 line to 0.80+ t, because the front switch selector is not present.
Also the cap placement in the jungla is different, and they are 3 caps in the RGB lines to ground so they don't float i suppose, also a 0 ohm resistor on YS2 to pull it low, they must be removed.

Keep the same setup that in my other monitor a DPDT switch having composite to jungla pin 15 and as option to the composite jack.
Also another switch to turn YS2 blanking on or off so i can keep using composite and svideo.

[soviet9922]

Some pictures showing cable placement and work progress.

[soviet9922]

The final product, very nice RGB image quality.
Some testing ATARI ST,QUORUM 128+,PS2 and Sega CD.

[Ryoandr]

Very cool. RGB hacking was needed for the 1X00 line, thanks for experimenting.

I found a mistake though, you marked to remove C503, C506, C507, R507 but they're not the ones to remove. They're C531, C532, C533, R554.

Also, I checked C129, it's connected to pin 53 Y2 IN, which isn't a simple flat voltage source, it has a signal coming from Pin 4 Y1 OUT via a transistor. So it might not be the best idea to use it as a 0.75 source.

[soviet9922]

Yes you are right i confused the serigraph text on the board is C533,C532,C531,R554 to be removed.
Also you are right about the point to get the voltage dont seem to be doing any negative effects but should be changed.

[xAzurexEonx]

very awesome!!

Do you find 17" enough? I've been debating this as 20"-25" seems to be a sweet spot.

Would you consider making an accurate guide and parts list?

Anyways very nice job!!

[soviet9922]

Yes i plan to do a complete guide, and yes i could prefer a 20" incher, 17 inches is not that small but for computers that have big borders like the Atari ST or the ZX Spectrum the usable image look small.

My problem is that my 20" PVM monitor died on my so i have to use this smaller ones.
Also own a 32" tv that have rgb hacked into it but is too big for vintage computers i keep it for videogame consoles.

[xAzurexEonx]

You've (and original article writer) inspired me to take this on.

What size wire did you use btw?

[soviet9922]

Are you spaking about the diameter of the wires i used for the mod ?.
Juse flat ribbon cable i just purchased a bunch of multicolored one from ebay quite cool for mods.

http://www.ebay.com/itm/1-27mm-Pitch-32 ... SwBOtY~YZF

The only special wires i used where shielded audio cable too hook the rca plugs to the scart connector mounted on the monitor.

[xAzurexEonx]

Yes those wires, very interesting it's from ribbon cable. I am use to only seeing very small wires for ribbons and these looked like they were either 24-22.

Going by pitch it looks like they are 22 awg.

(sorry for so any questions) What was your reasoning behind the RCA jacks for audio?

[soviet9922]

I was out of 3.5 mm jacks that are chassis mountable, so i go for RCA females i have a shitload of them
Also old audio amps have RCA audio inputs, so this is not a problem for me.
Remember to use shielded cable for this or you are going to get a lot of noise in your audio.

[xAzurexEonx]

Gotcha.

Haha Im so antsy about getting my JVCs in, now delayed =(.

[Namingway_PL]

Hi everyone.
Does anybody know, is it possible to set the H/V screen size in the JVC TM-H150CG?

[LEGENOARYNINLIA]

Hi everyone.
Does anybody know, is it possible to set the H/V screen size in the JVC TM-H150CG?

Try this: viewtopic.php?p=1225546#p1225546

[xAzurexEonx]

Are there any issues with sync? Is everything CSync?

[soviet9922]

If you feed sync to composite and force Y2 to rgb you can get almost any sync to work composite sync example.
But if you feed sync to the jungla sync pin must be pure sync if not you will see bad sync issues.

[xAzurexEonx]

I believe I understand.

I finally got mine in, thanks to this thread!!

Sad news first...the seller well...was an idiot...zero protection just cardboard box. So one front bezel was destroyed, shifting the buttons around and out of place. The other has cracks but not as bad.

Now to say these JVCs aren't as well built as Sonys isn't true because they work and are BEAUTIFUL!!

The controls are FAR better than the Sony PVM/BVMs. In under 5 mins I was able to match settings between the monitors. There are a few more combo buttons to get into the deeper menus, but this also allows you to get to what you need rather than cycling to through everything.

I'll stop, I'm just rather impressed that I'm not actually downgrading.

[soviet9922]

Very usual people send you a 20k monitor in a bare cardboard box, is the recipe for disaster!.
Good news that you already modded yours successfully i still have 3 more JVC 15" to hack RGB into.
So i feel creative and going to try different things .