TV RGB mod thread

[leonk]

Finally got around to complete this project. The surgery was done on a 2003 Sony 27FS100 .. what a great CRT.

progress pictures:





The quick connects I decided to use is DB15. The 75 ohm and 0.1uF caps were all installed on the female SCART port. The 4PDT switch was installed with composite video down, RGB up. Composite video and audio left / audio right were fed into Video 3 / composite input.





End results / what I discovered:

Because I use mostly composite video for sync, if I don't feed 5V via SCART connector, the TV just thinks regular composite video is being fed in. This is a great A/B test as one can quickly see the difference in quality just by flicking the switch. This TV allows you to set color temperature, brightness, etc. All these pictures settings effect RGB! So set desirable settings in composite mode, and then switch to RGB to play.

Sega Genesis model 1 csync / sync booster SCART cable:





This system just shines in RGB on this TV. The best picture I've seen. Equivalent in every way to my 20" PVM.

Nintendo SNES mini with RGB amp:



Exact same color and brightness as composite video. Much cleaner picture.

NESRGB in my Top Loader (using exact same sync on composite video cable as the SNES):

This is where I run into trouble. This is what it looks in regular composite video from NESRGB:



Now same picture in RGB:



Yes, it actually does look "darker".

SMB3 world 1 level 1 shows the issue best:



Notice how much darker everything is. Also, the sky doesn't have uniform color. That white bloom is actually there! The other thing I noticed is "noise" in the picture. Diagonal lines of "noise" every few pixels apart, across the entire picture. Especially visible in the solid colors. Very hard to photograph, but if you look at the big "Mario Bros" title screen, you can clearly see it in the blue text.

This system looks and acts perfectly on my PVM .. I play it every day and never an issue.

2/13/2015: The issue is the cable. The diagonal lines are there in the SNES image above as well. When one uses CSYNC cables instead of sync on composite video, all the problems go away.

[leonk]

UPDATE:

I switched my composite video from V to CS# on NESRGB and all the problems went away!





I can confirm that it is RGB, and looks AMAZING. If I switch to comp video input, the video goes away but audio remains.

2/13/2015: ignore the picture shift to the right. I was playing around in the service menu and forgot to correct it.

[darknezz19]

Nice work leonk. Got mine going yesterday as well and am happy with the results. Had to terminate with 100ohm instead of 75 to get the brightness up. Other than that nothing out of the usual.

http://imgur.com/a/FzNr7

Edit: You can check out the work flow log in the link below if you are interested.

https://www.reddit.com/r/crtgaming/comm ... d_toshiba/

[Voultar]

Nice work leonk. Got mine going yesterday as well and am happy with the results. Had to terminate with 100ohm instead of 75 to get the brightness up. Other than that nothing out of the usual.

Did you not put couple caps on your terminations? If you don't restore the black level, you're not going to have a purdy picture.

100 ohm resistors won't match the impedance of your 75ohm load vidya signals.

[leonk]

Hey Voultar, how do you connect your NESRGB to your RGB modded NES? CSYNC? Any issues? cropping?

[Voultar]

Hey Voultar, how do you connect your NESRGB to your RGB modded NES? CSYNC? Any issues? cropping?

Composite Sync all the way.

I can see Composite Video or Luma creating some line delay that will cause a slight horizontal shift.

Keep in mind. Composite Video, and S-Video go through several post processing filters, such as comb for example.

RGB doesn't, and that in itself will produce a line delay, depending on how the jungle handles it. You can have a slight horizontal shift (typically in the east direction).

[leonk]

UPDATE:

- Next, tried my TG16 with Tim's AV-Driver in it. Uses composite sync:





Just perfect. Notice no jail bars, perfect saturation. This thing is a dream.

But I did notice something, and confirmed it with all other sources. The menu system is still visible!!! I use 5V source from the console. When I press MENU, nothing is visible except for a faint shadow of the menu - I can almost make it out. On black screen, the shadow reads "Video 3!!"

Only way I think this can happen is if the original blanking pin is cross talking somehow! But the only way they come close to one another is in the switch. Bad switch!?

[mikejmoffitt]

The MCU's 5V blanking output is influencing the line a tiny bit still. There are actually two OSD Y outputs on the MCU. One is for solid areas, and one is for "outlines". That may be related, and you can try taking both out of circuit. It's kind of handy to have the menu noise there if you need to use it.

If you use S-video input for composite sync you might have your horizontal shift solved. Otherwise, the service menu will help you.

[leonk]

...

[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).