(Solved) Trouble with diagonal interference lines on crt's

[Taiyaki]

Been having the strangest occurrence on a few consoles only (NES, SNES and Genesis) where on all games at all times there is some form of interference (light diagonal scrolling lines that move from bottom left to top right in a continuous fashion), they are most noticeable in games that have solid areas on screen.


I have tried multiple power supplies, connections (and cables) and even multiple consoles for the Genesis (high def, non high def etc) and yet all still have the same symptoms. I thought it could be the tv but I have tried on three different flat screen late Trinitrons, one being completely isolated from anything else in the house with just the tv and one console.


I tried FFII on the SNES and can see the lines over the blue menus while the exact same game on the PS1 (in FF Chronicles) doesn't have any lines at all as is crystal clear and stable.


Finally the only way to get rid of them that I could find is through the image "Tilt" function of my Trinitron's. As I change the tilt it alters the speed and intensity of these lines (which I wish I could get on pictures but I can't seem to). If I tilt the picture to the extremes (either -5 or +5 I eliminate it completely but end up with a picture so out of center that it's even more unplayable.


These lines don't display on PVM's or LCD's at all, only on the Trinitron TV's (I only have the later flat screen models to test with, FS120 and two FV300's).


Wish I could figure out what is going on as it drives me crazy on some games.


I was wondering whether I should try buying coax 75ohm terminators for the tv coax ends as I don't have cable boxes connected to them but not sure that has any relation to this.


Any help from the pros here would be hugely appreciated! I can't understate how appreciative I'd be if someone could help me solve this issue.


Thank you.

[FinalBaton]

I don't think putting terminators will do anything. I don't on my fv300 and the pic doesn't have interference. Besides, consumer tvs usually self-terminate.

It would be quite the coincidence if both the snes and genesis started going bad at the same time, so I don't think that's it.

Could it be that your scart cables don't play nice with your YUV transcoder and/or TV because of the cables' sync type maybe? I don't know, just throwing that out there

[Taiyaki]

I use S-Video but I tried scart through a YUV encoder and even composite on both and it makes no difference. I actually have several Genesis consoles and all have them have this issue so it seems really unlikely to be the consoles.


It's also probably not the tv's since I have 3 different Trinitrons and all do it and the same games on PS1 or PS2 collections don't display these lines. I don't know where to go next in solving this issue. : /


The only notable aspect as far as the tv is concerned would be the fact that the rotation or tilt as it's called in the menus of my Trinitrons is the only setting that affects them. Obviously as my sets are perfect at around 0 or -1 or +1 pushing it to the extremes of -5 or +5 where the lines disappear result in an unplayable picture all slanted in on direction.


Do you use a surge protector that cleans noise (I think they're a more accurate name for those)? Or do you use a regular surge protector and still have no lines? The thing is on the SNES it's not as noticeable because the snes displays more details in games, I actually only noticed it when I started looking for it to figure out whether my other consoles had the same problem as my Genesis. On the Genesis there are many games that use solid or two pattern backgrounds and on those the diagonal scrolling interference type lines are very noticeable, and frankly are exhausting to the eyes.

[Guspaz]

I've not seen that particular type of interference on any console connected to either my Sony PVM, LCD monitor, or projector, including PS1 (Composite), SNES (Composite/S-Video/RGB), Gamecube (S-Video), or NES (Composite).

That's not to say that composite video isn't giving dot crawl and other artifacts, but not diagonal lines.

[Taiyaki]

I think I should describe the lines better by adding that they're transparent lines, these are not solid lines crossing through the picture, it's not noticeable on games with heavy graphics such as Comix Zone or Super Metroid (except the sky area in the opening of Super Metroid). But in games with simpler graphics such as FFII or Shining Force you can see the light lines pulsating through the solid blue skies or near solid green plains constantly and it's very irritating.

[Guspaz]

Are you using OEM or third party power bricks? Are you using devices out-of-region (IE a 60Hz/110v SNES in the 50Hz/240v region via a step-down transformer)?

HD Retrovision did a post on their kickstarter about this:

https://www.kickstarter.com/projects/hd ... ts/1425170

I've not seen anything like what you describe, but all of my power bricks are OEM (from Nintendo or Sony).

[Taiyaki]

I use the official Famicom power adapter for my super famicom and I use the original Genesis power adapter for my Japanese Mega Drive but I've also tried the Sega Trio by Retrogamecave. I thought maybe this was a problem of the 100V on a 110-120V socket in the US but even my American Sega CDX with it's original power supply has the lines too. It only happens on my NES (only have 1 unit), Super Famicom (only 1 unit) and 3 Genesis units (2x Gen1 and 1x Sega CDX). I've never heard of this either, it's so strange. I will try to get pictures of it but I don't expect it will show well.


I have a decent power surge (and I've tried in different outlets as well) but I don't think it does any noise filtering like the much more advanced types do. However I always thought dirty power shows itself in horizontal bars of noise scrolling downwards or upwards. Never seen diagonal ones like these.

[Josh128]

Sounds very similar to problems I had in the past. Could be 1 of 2 things:

1.) Sounds like jailbars. Try changing your sync. Experiment with Luma, C-sync, and composite video. C-sync should be best to eliminate jailbars, but not always. If you are already using c-sync, try both of the others and see if either clears it.

2.) Bad/ cheap cables and/or switch or selector. I had a Philips component switch that made ALL of my RGB modded systems going through it have the exact problem you are describing-- faint, almost transparent diagonal lines, all parallel to each other, scrolling slowly across the image.

Change cables and/or lose the switch to check.

[mvsfan]

I had bought a cheap snes s-video cable one time and it was producing diagonal interference because it was using composite video for sync and luma.

A properly wired s-video cable like the Tomee ones dont have that interference. Although they too seem cheaply made they havent given me any video issues.

When i moved up to scart i was also getting the same interference with a composite video sync scart cable.

I moved the sync over to csync and the problem completely went away.

Now i ONLY use csync or sync on luma scart cables depending on the console.

[Taiyaki]

Thanks to both of you for pointing those things out.


I did some further testing including on consoles that have no issues (these consoles include the Saturn, PS1, N64, Dreamcast and PS2). When trying with composite, and S-video (official cables for all systems) I have no visible interference issues.


The NES has these lines but they're much softer and less noticeable than on the SNES and Genesis. I noticed unfortunately my Gamecube has it too but it's also softer and due to the much more graphically detailed games on the system they don't get seen much. I tried taking pictures and even after half an hour trying over and over with different settings and zoom levels they just don't show up.


Again I'm trying this on 3 different newer flat type Trinitron TV's and all display the same.
Have tried on power surges, separate outlets for a single console and the tv isolated from anything else etc, still same results (have tried with multiple power adapters and connections on each of the systems with this issue).


I think Josh128's description sounds identical to the lines I have. Did you have these lines using composite connections too? If so it may be worth my modding my SNES for Csync (currently my model doesn't have Csync).

[mvsfan]

do you have a 1-chip-03 ?

getting csync on it is a 1-wire mod.

Oh, i first noticed the lines on s-video.

another thing as people have mentioned is your power supply. a while back I had an snes that i hadnt used in a while and it was showing a white bar across the top of the screen on a Crt, and it would not even sync on my DLP tv it just said no signal.

I tried a different power supply and it worked normal.

[Taiyaki]

MVSFan> I have a first model Super Famicom (I believe a non 1Chip) but it doesn't seem to take Csync (my Csync scart gives a black screen on the system but does work on my modded N64 (by Pasky ).


So you mean the diagonal lines interference you were having on S-video and interference on the composite sync wired scart cable were mostly identical? If so then there may be hope (In my case all connections give the identical interference type). You bring up a great point that I haven't tried yet and that's getting a Csync connection.


My S-video cable is the official Japanese Snes cable. Do you think the Tomee one might be better built? Could it be Nintendo made an S-video cable that uses composite as sync? o_O
For some reason when I move the cable to the N64 it works fine with no interference lines, but maybe that doesn't mean anything.


I have many power supplies (official ones) and unfortunately that didn't make a difference, thanks for the advice though.


By the way to everyone: Merry Christmas / Happy Holidays!

[Taiyaki]

I found this cable which appears to be of good quality:

http://www.ebay.com/itm/SUPER-NINTENDO- ... 1489936431?

Will try this out and report back with results.

[Taiyaki]

After doing a lot more research on this on google and yahoo I've now found at least three instances of other people on various message boards and sites complaining about the exact same issue and having no luck eliminating it.
(command F> "diagonal" or "lines" for easy browsing)

http://www.theisozone.com/forum/viewtop ... 64&t=24156

http://www.sega-16.com/forum/showthread ... post559423

http://nfggames.com/forum2/index.php?topic=1592.400

http://forum.digitpress.com/forum/showt ... ost1828781


Glad to see some documentation on the issue. The lines that I get look like ＼＼＼ (moving upwards).

One solution in the first link:

Also, for some consoles that natively support S-Video, the S-Video signal isn't very good and requires modification anyway. For instance, the older revisions of the Super Nintendo have an issue with diagonal lines that must be corrected with about 470 ohms on the chroma line. The only way to correct that is to make a direct S-Video port with the resistor on the line.

Problem is I get them with composite and rgb using composite video as sync as well.

The second link has a similar message from user Drakon whom I believe is a schmups member as I've seen his name before also offers the same solution. Hoping maybe he can enlighten with his experiences on this issue for future reference for all of us who encounter this problem.

[mvsfan]

if you dont have another scart cable you can try moving the composite video sync over to composite sync pin in the multiout connector on the cable. only problem is you may have trouble putting it back together if you change it. many of those scart cable multiouts ends are glued. theres basically nowhere to get multiout plugs so people usually take one from an inexpensive 3rd party composite cable.

also, he said in that post that many s-video cables are wired wrong. they are.

[Taiyaki]

...he said in that post that many s-video cables are wired wrong. they are.

Could that hold true for the official Japanese Super Famicom S-video cables too? Those are the ones I use on the SNES. For the Genesis I use a plain S-video to S-video cable.

I ordered a csync Genesis scart cable to try out. Will keep this thread updated with the results.

[Guspaz]

The genesis doesn't support S-Video, so either that's a modded console (with its own potential issues), or some fake cable that just runs composite signals to an s-video connector.

[Taiyaki]

The genesis doesn't support S-Video, so either that's a modded console (with its own potential issues), or some fake cable that just runs composite signals to an s-video connector.

It's a modded Genesis but I have a non modded one too (and different model, non high def graphics model) and it also has gets the scrolling diagonal lines through composite.

[Josh128]

The csync SCART cable should fix it if its a legit cable. As mentioned before, the Genesis does not have S-Video out so something strange is amiss with that.

With true C-sync RGB, your issue will be solved unless you have something wrong with your TV or something in your house causing interference.

[mvsfan]

Also - the original superfamicom RGB cables most of them have Bad, Leaking capacitors in them by now.
Because of that fact, your often better off buying a 3rd party scart cable with new caps unless you know how to replace them and clean up the electrolyte mess.

[Taiyaki]

Ok I received the csync cable for the Genesis, hooked it up and... it made no difference.


At this point I'm concluding the problem must be a combination of factors instead of a single one, at the moment I feel it might be the combination of these older consoles (nes, gen, snes) on later Trinitron crt's (all 4 of the crt's I tried them on are 02~03 tubes). I know some don't see them on their later Trinitrons so then that adds perhaps the possibility of the electrical wiring having some form of impact. When I hook them up on lcd's I don't see the problem. I also didn't see it on my Toshiba crt but that was a 13 inch. Again I have tried multiple consoles and power adapters as well as connections and no difference.


What do you think of this type of device:

http://www.cs1.net/products/audio_authority/1184.htm



I saw someone else bring this up in a different thread for a different problem. Based on the description it sounds as though it might work but at that price I'd like to feel that it's more likely than not to resolve the issue. : /


Quote from the product:
Designed to solve the problem of rolling video hum bars caused by AC-line related noise due to ground loops in coaxial cabling.


Not familiar with Ground loops but does it sound like my problem might a ground loop issue?


Here's another page about it:

http://www.svideo.com/41146a.html


Based on what they say:
Ground loops manifest themselves in the form of hum bars called herringbone (diagonal lines on the screen) and AC beat (a wide, barely visible bar that rolls from the bottom to the top of the screen).


That sounds right, and I happen to use S-video for those three consoles. So I went ahead and ordered. Will update once I receive it.


EDIT: Turns out the S-video ones are all discontinued. I looked for a couple of hours all over the web and could only find one brand (Kramer) still making them but they don't carry in the US and it costs over $100. : /
So I went ahead with Component since they're much cheaper (can be bought for around ~$60). Will update once it arrives and I try it out.

[Josh128]

I have a 2006 model Trinitron and I can confirm I dont have the diagonal interference with any connection-- composite, SVideo, or RGB/component.

Any chance you could photograph the problem and post it here?

[Taiyaki]

I have a 2006 model Trinitron and I can confirm I dont have the diagonal interference with any connection-- composite, SVideo, or RGB/component.

Any chance you could photograph the problem and post it here?

I tried over and over again to get the lines to show on my camera and I've had no luck what so ever. Picture sometimes even shows other lines or wavy lines that don't show in the picture at all in person.


The closest video I've found is this one here:

http://avaa.bavc.org/artifactatlas/inde ... erringbone


The video there looks exactly like what I see except that the lines I get are a little most spaced apart from each other (I can change spacing by tilting the picture in the mneus but obviously that's not a solution). Just like in the video the lines move in the same direction, semi transparent diagonal lines going from bottom left to top right. Only happens on NES (very faint lines), Genesis and SNES (more pronounced on these two).

[Josh128]

Yeah, thats exactly what I was describing earlier-- 1 was caused by a cheap component switcher, 1 was caused by using the NESRGB composite as sync.

[Taiyaki]

Yeah, thats exactly what I was describing earlier-- 1 was caused by a cheap component switcher, 1 was caused by using the NESRGB composite as sync.

I'd be curious to know whether you get that when hooking the systems up via composite though. Unfortunately in my setup this happens with composite and s-video (it's modded for S-video) as well. Happens with csync on the genesis as well (now that I could finally test it). I'll shortly find out whether or not the isolation transformer gets rid of this but my hunch is that if anything does it will probably be this.

Every other console looks gorgeous on my crt's except the ones that have those lines going through the picture like that (the intensity is much lower, like around 10 visible lines at a time instead of the 30-40 seen in that video, but it's still unbelievably distracting).

[Josh128]

I dont get the lines by hooking them up to composite. Ive tried SNES, Genesis, N64, and Saturn. No lines.

[Taiyaki]

I dont get the lines by hooking them up to composite. Ive tried SNES, Genesis, N64, and Saturn. No lines.

Thanks for trying, I appreciate it!


I read that ground loops should only occur on devices that have 3 prong power cords and from what I've seen all the gaming systems use 2 prongs.

Since I was getting really confused over this I called a company that produces these video isolators and inquired about them. According to the person I spoke to even if the source is not grounded with 3 prong power cords there can still be imperfections that can creep into the video signal through the power even when the power is perfect for most other applications. He appeared quite confident a video isolator would clean that up.

Now I'm waiting on the one I bought and will update this thread with the results.

[Taiyaki]

Here's a rather big update on the issue:


First I tried a video isolation transformer and learned that this issue is not a ground loop problem. Video isolation transformers turned out to not even work because it blocks the dc current. The alternative is a video hum isolator but they don't eliminate these hum lines either.


When I returned the product I was advised to try out a power line conditioner in case the power was corrupting the video from the source. I tried one out and although they are awesome for other features, they do not get rid of them, indicating the power is not to blame either.




Finally I found the culprit. It turns out to be internal interference cause by the onboard microprocessor.

Apparently the onboard tilt function affecting the hum is the give away.

The solution is to tilt the yoke centered around the 3 menu tilt points where the noise dissipates which on the boards used on early 00' flat Trinitron models in 20 and 24 inch models is -5, -4, -3 (-3 still shows some noise on the Genesis, and very lightly on the SNES), ideally I guess centering the yoke on -4 should be perfect. Bigger sets may have the interference leak in at different values (or perhaps not at all?).

This then requires recalibrating everything unfortunately (geometry, convergence, and possibly purity).


I found this out because someone's else's same era Trinitron had this problem too. I then read some documentation on this from some tech folks who wrote about it on some old website.


I think it's important to know that the interference is not visible to some people apparently (it's on the high frequency line and is very very thin). The only system I can get everyone to see it on is the Genesis with certain backgrounds.

I must be a little more sensitive to the video hum than most as I can also see it on the SNES and NES (more so the SNES than NES). : /


If in the future anyone else ever has this problem the easiest way to work on it is to use an early Genesis game which uses solid backgrounds especially anything blue, green or yellow, and you should see the lines and the effect changing the tilt has on them. This should help if you decide to pivot the yoke to get the sweet spot (assuming you're using an FS or FV model in 20-24 inch with the same board I have on my sets this spot should be -4).

Meanwhile I'm off to calibrating my FV300's sets...

[telemetry]

Thanks for the information regarding your results.

I've experienced the hemingbone-style interference when using my GameCube with S-video, but my understanding was that it was likely due to bad third-party cables.

Very interesting to hear that the video isolator and hum eliminator didn't help. I never thought about the microprocessor being the cause.

Isn't it true in some TVs that different inputs have different microprocessor paths? Ex., I remember Fudoh mentioned once that RGB processing on Sony Wega's was entirely different (and much lower quality) than the component processing.

In that case it seems like maybe a RGB connection method might yield better (or maybe just different) results from the S-video.

[Taiyaki]

I believe you're correct, however in this case, from what I understand, this interference is transmitted to the set regardless of inputs. Even happens with the front inputs.


What I don't quite get is with FFII on the SNES (aka FFIV) the lines were visible but not the same game (FF Chronicles) on PS1. Apparently newer consoles render them invisible, at least to me eyes. Wish there were some explanation for this. Maybe someone with a higher sensitivity would see them.

I suppose it's possible the vast majority of gamers have this faint high frequency interference on some set or other and never see it at all.


I set the yokes in the right position and glued them with RTV. Turns out the turn was so slight there wasn't much of anything that was thrown off. I did use the this opportunity to improve convergence where I could. No more lines, excellent picture. This thread has a happy ending.