TV RGB mod thread

[Voultar]

You have a nice sync input right on the Jungle I/C. Try terminating sync (with a 75 ohm load) directly to the sync input pin on the Jungle I/C.

Composite Video and Luma go through a couple of processes before the signal's handed off. This is the culprit for line day. Terminating your sync source (properly) directly to the Jungle I/C should mitigate that horizontal phase delay.

[leonk]

ARGGGG .. I'm a dummy. I finally figured it out.

- all my Sega Genesis consoles are CSYNC with Sync booster - works great
- my TG16 is CSYNC - works great
- my PS2 is sync on luma (being fed into composite video port) - works great
- my Nintendo multiAV plug is composite video sync - TROUBLE
--> on SNES and N64 it looks great, but there is some diagonal noise (the video!)
--> on NESRGB, you get issues with too dark picture, noise, blooming - again, composite video

When I switched my NESRGB to composite sync / csync, it cleaned up, but was pushed to the right. But then I noticed ALL consoles were pushed to the right. And then I remembered! I changed HPOS service menu option when I first got the TV! I restored it to factory setting and all is perfect.

I'm finally done with this thing! Moral of the story: RGB modded TV (especially these Sony Trinitron) require CSYNC. Sync on composite video will not work.

[mikejmoffitt]

I'm finally done with this thing! Moral of the story: RGB modded TV (especially these Sony Trinitron) require CSYNC. Sync on composite video will not work.

Whoa whoa, let's not just say stuff - in the past, this used to be what all the cool kids did. It certainly works for me, though I prefer composite sync always. That said, it's good that you resolved your issues by using C-Sync.

[leonk]

I'm finally done with this thing! Moral of the story: RGB modded TV (especially these Sony Trinitron) require CSYNC. Sync on composite video will not work.

Whoa whoa, let's not just say stuff - in the past, this used to be what all the cool kids did. It certainly works for me, though I prefer composite sync always. That said, it's good that you resolved your issues by using C-Sync.

We have the exact same TV!

With composite video sync, the snes and n64 shows diagonal noise is solid colors. With csync it doesn't.

Have you noticed this?

[mikejmoffitt]

I realized I'd confused the TV from my CL searches with the TV in my post. I have a KV-27FS42, which I think is one generation different. That said, things are very similar. I was about to get an FS100 but then I decided to bring my television from home and forewent the search.

I have no diagonal noise in my video with composite video as a sync source.

[Voultar]

I'm finally done with this thing! Moral of the story: RGB modded TV (especially these Sony Trinitron) require CSYNC. Sync on composite video will not work.

Whoa whoa, let's not just say stuff - in the past, this used to be what all the cool kids did. It certainly works for me, though I prefer composite sync always. That said, it's good that you resolved your issues by using C-Sync.

We have the exact same TV!

With composite video sync, the snes and n64 shows diagonal noise is solid colors. With csync it doesn't.

Have you noticed this?

The diagonal lines you refer to are a result of chroma data bleed in your sync source. Remarkably common. Using luma or composite sync will 100% remedy that.

[tjsynkral]

I'm finally done with this thing! Moral of the story: RGB modded TV (especially these Sony Trinitron) require CSYNC. Sync on composite video will not work.

I didn't have any trouble with sync on composite video on my Zenith, using the cheapo Chinese SCART cables for PS1 and Nintendo multi-out. It could be a problem with your SCART cable. One of mine was wired improperly with an open ground.

Also make sure you are grabbing the correct pin for composite video (one is input and one is output, I can't recall which one was correct in my situation and maybe some SCART cables are inconsistent on for whom we're asking input vs output anyway). I saw a similar problem to yours with the diagonal lines and color bleeding, and then I reversed it and that solved the problem.

EDIT: Now that I've tried this on a Trinitron, the diagonal lines on composite video sync are definitely an issue with Trinitrons, probably from the comb filter. Also regardless of composite sync or composite video, there is a large horizontal picture shift introduced by the comb filter. Those problems both go away by putting the sync into Y instead of a composite input.

EDIT 2: Never mind, I get the weird diagonal lines on Y too (but I'm leaving it there for the horizontal shift fix.) I must have been missing a wire because I'm sure that I did see a good RGB picture from my composite video sync cable when I was testing with Y earlier, but now that it's all put together, only a composite sync will do.

[leonk]

Nope. I got a very good / expensive SCART cable - made by that lady on eBay. Perfectly wired, with extra shielded cable and extra ground wires.

I ended opening the Nintendo multiAV end and moving the sync line (pin 20 on scart?) from composite video to csync (pin 4 on multiAV). It works perfectly now.

[Guspaz]

Is there any sort of precedence for doing an RGB mod on a PVM? I've got three PVM-14N5U sitting in my apartment. From the outside, they appear identical to the 14N6U, which does do RGB, only they have one less input button on the front, and the back panel space for the RGB inputs is blank.

[22point8]

Is there any sort of precedence for doing an RGB mod on a PVM? I've got three PVM-14N5U sitting in my apartment. From the outside, they appear identical to the 14N6U, which does do RGB, only they have one less input button on the front, and the back panel space for the RGB inputs is blank.

Pretty sure I saw a topic at either assembler or neogeo forum on that.

EDIT: http://assemblergames.com/l/threads/mod ... uts.52392/

[mikejmoffitt]

I picked up another 25" TV today intending to do a tube swap on a Neo-Geo machine. If the tube swap doesn't work out, it's still a good tube and TV, so I'll see about RGB modding it. At a glance the OSD looks RGB-driven, so I bet it will not be difficult.

[capsulej]

Ever get the feeling that your in way over your head?

[leonk]

The above is wrong. The S100 has a seperate switching power supply. The chassis is not "hot" in the same sense that 80's arcade monitors have hot chassis.

[bobrocks95]

To qualify that statement a little bit, still do be extremely cautious because it'd be really stupid to die while modding your television with an RGB input.

[leonk]

To qualify that statement a little bit, still do be extremely cautious because it'd be really stupid to die while modding your television with an RGB input.

agreed. Even though this modern TV self-discharges the anode, proper manual discharging must be followed. Only when the main chassis is disconnect from CRT/neckboard, PSU and is fully removed from the TV that you should work on it. Only when it's fully assembled should you try to power it back on.

Before attempting this mod, experience with working on CRT's is a must (e.g. doing cap kits on arcade monitors)

[MKL]

The above is wrong. The S100 has a seperate switching power supply. The chassis is not "hot" in the same sense that 80's arcade monitors have hot chassis.

Even if the chassis has a SMPS, when using test equipment in the primary section of the power supply (i.e. before the isolation provided by the built-in transformer) an isolation transformer must be used and if any instruments are earthed (e.g. oscilloscope) the earth must be disconnected. This is not necessary when working in other parts of the chassis (deflection, etc.).

[leonk]

Exactly. The primary PSU on the FS100 is a seperate PCB. There's no reason for you to even touch it if all you're doing is an RGB mod.

All RGB points are in the low voltage section of the main board.

[tjsynkral]

Don't discharge the anode... don't go anywhere near the anode. Leave the anode cap alone. It's there to protect you.

[leonk]

Don't discharge the anode... don't go anywhere near the anode. Leave the anode cap alone. It's there to protect you.

??? How are you supposed to work on the main chassis if the anode is still attached to the CRT? You need to slide the chassis out in order to get to the jungle IC. You have no choice but to remove it. Once the chassis is freed, it's much easier to do the required modifications on your workbench.

[mikejmoffitt]

You don't have to remove the chassis in many cases, but I'd recommend discharging the tube.

[tjsynkral]

Don't discharge the anode... don't go anywhere near the anode. Leave the anode cap alone. It's there to protect you.

??? How are you supposed to work on the main chassis if the anode is still attached to the CRT? You need to slide the chassis out in order to get to the jungle IC. You have no choice but to remove it. Once the chassis is freed, it's much easier to do the required modifications on your workbench.

I left the anode cap in and connected to the FBT, but my TV had a decent amount of slack in the wire so getting the PCB out was no problem. If you have no choice but to remove the anode cap, I guess that's another option, but aside from the discharging process that whole area feels fragile to me and you can count on needing several trips in and out of the TV on your first attempt (or maybe even your first attempt for every make and model).

[capsulej]

Hmm.. So i tried this on a kv-27fs100 and managed to get a nice rolling picture. Whats strange is that the RGB image comes through perfectly, from what little bit of it i can catch. When i switch the tv to composite (im using a RCA connector to pull sync from the av input) the picture comes through just fine, so i don't think its a sync issue. Also tried pulling the sync from the svideo connector but i get the same problem.

[tjsynkral]

Hmm.. So i tried this on a kv-27fs100 and managed to get a nice rolling picture. Whats strange is that the RGB image comes through perfectly, from what little bit of it i can catch. When i switch the tv to composite (im using a RCA connector to pull sync from the av input) the picture comes through just fine, so i don't think its a sync issue. Also tried pulling the sync from the svideo connector but i get the same problem.

You need to switch the TV to the composite input and feed RGB into the OSD with the composite behind it as sync. Make sure the original composite video is disconnected and only your SCART composite video pin is fed into that input.

[tjsynkral]

Working on my next test subject, a KV-27FS13. The RGB looks fantastic except where the picture is black. What I see is more gray and I get crawling swirl marks. I can reduce the effect by dropping the brightness, but of course that sacrifices some brightness.

Each color is terminated to ground with 75 ohms and running through a .015 cap (originally set used .01, but I also tried with 0.1 and I don't see a picture difference between 0.1 and .015).

Anybody have any ideas?


Huge version: http://gadgetscope.com/tests/kv27fs13a.jpg


Huge version: http://gadgetscope.com/tests/kv27fs13b.jpg

(Note, I know I still need to tune the convergence a bit more... This set is being a bit difficult to tune.)

[atheistgod1999]

How about a Toshiba 27A43? It's an awesome TV that, despite being a shadow mask, almost looks like an aperture grille due to how many TVL it has. It was manufactured in 2003, any way to get RGB? I'd like to mod it because it handles luma/chroma signals better than the BVM-20F1U and I don't feel like modding everything for RGB (and besides, the unscanned lines (what the rest of you call "scanlines") are too thick on the BVM while they're just right on the Toshiba). It's a very similar model (might even be the same, in fact) to the ones MyLifeInGaming use when they use CRTs.

[tjsynkral]

How about a Toshiba 27A43? It's an awesome TV that, despite being a shadow mask, almost looks like an aperture grille due to how many TVL it has. It was manufactured in 2003, any way to get the Jungle IC?

Looks like that uses a OEC7090A jungle IC. That service manual isn't hard to find.

[mvsfan]

There are also some Jvc tvs that spec at 800 lines. with a tv like that ive stopped looking for a 20" PVM.

Ive tried twice to buy one of these tvs and just missed them.

[tjsynkral]

Update on the Trinitron. As I noted in an edit above, composite video sync causes issues on the Trinitrons so a composite sync cable will be a must. The best results come from using AV4 and putting composite video/sync into the Y channel. My interference trouble was a combination of poor quality cable, long cable length, and locating the cable near some noisy components under the motherboard, so these are things you have to be careful of. I'd tried to use the front AV jacks as the source but between the composite video troubles, the location being hard to get to and interference prone, and those two audio jacks being short to ground when no cable is present (until I cut those traces) I suggest staying away from that area. I wired sound directly to the K board interface.

When everything is done I'll try and get some pictures. I still have raw video recorded from the Zenith project but no time to edit videos currently.

I still need to adjust the focus, yokes, and convergence on this beast, and mount the SCART (I'm thinking of rigging some sort of quick-release because permanently attaching it to the back cover isn't great for maintenance, not that I really want to ever open this TV again).

Sonic looks great and that game really shows off any RGB project. It looks just like a 27 inch PVM and I am having a hard time keeping myself from playing Sonic or the SNES test games I have here. The sound quality is excellent too, considering most CRTs from that era had soup can speakers (and don't even get me started on the speakers that come in 1-inch-thin LCDs).

[leonk]

Thanks for sharing. As I posted a few pages back, I too found composite video input used for sync is troublesome for the Sony CRT I had. CSYNC resolved my problem.

I installed a SCART female port in the back and jumped the audio from the SCART port to the red/white audio ports on the same composite video port.

This is not an issue because you can always use SCART extension cords.

[Einzelherz]

Possibly a stupid question but: Aside from the color issues that can happen with certain RGB->Component converters, are any of you guys noticing a significant gain in picture quality? I get the simplicity aspect of not having to deal with a converter, but I was curious if there are any more benefits.