have you tried the VGA output of a much newer GPU (Geforce 4 or better).

I've seen shimmering like this on extremely old ISA cards.

This might be caused by a bad video card. I would have to agree with canthearu on having those problems with old ISA cards. Maybe it's one of those cases where you would have to get a replacement graphics card that's better...

This is how graphics output looks like if you remove the capacitors from VGA.
If they have lost capacity, they sort of removed themselves.
So I think, recap issue.

Edit: In this case, it looks like the caps of the panel/its controller are bad.

Alright, thanks m'dudes.

The thing is, the cards I tested with are both PCI: S3 Trio and CT65554/5.

canthearu wrote:

have you tried the VGA output of a much newer GPU (Geforce 4 or better).

Yeah, should have done that right away. I tried my EeePC (Intel GMA) and got the same result. My best guess now is retardware's conclusion: bad panel or controller board! I was hoping to confirm this 100% before I return the panel/board to the retailer and get a different one.

Yeah, if it still does that on a newer video card, then definitely fault in the LCD controller board.

I think i saw something similar with a bad vga cable before.

Solarstorm wrote:

I think i saw something similar with a bad vga cable before.

Ah, good catch! I should have thought of that.

Tested a different VGA cable and, lo and behold, most of the lines cleared up most of the time... however, the picture still flickers from time to time, some screens (post screen, Windows desktop) are downright still, while others (Windows explorer, games) still produce jaggedy lines.

Might still be a combination of factors? or I simply need a really well made DSUB cable?

Thanks for the input so far.

Might still be a shielding problem, since it's bare electronics running openly unshielded i guess or still some bad connections.

had that same issue with my s3 virge dx, with a crappy vga cable, used a different one and it went away and i got a clear picture.

If it flickers more when you move/twist the cable a bit, then there might be some connector damage or too much rust.

henryVK wrote:

Might still be a combination of factors? or I simply need a really well made DSUB cable?

Could be an issue with the LCD driver or it's PSU as well. If the caps are failing and the power provided is noisy, it'll act up. The worse the input signal, the worse it gets. So getting the input signal to be as clean as possible is always a good thing (even if there were no other issues) but if a good quality cable is not fully fixing the problem then chances it's not the only problem you have. Oh and same goes for video cards but if you can get a stable picture on other displays and not this one then obviously it's the culprit.

Solarstorm wrote:

Might still be a shielding problem, since it's bare electronics running openly unshielded i guess or still some bad connections.

I was wondering about this from the start!

I think the important clue might be that the LCD driver board's OSD is also subject to these interferences, so it actually shouldn't be the VGA signal that produces (most) of the noise because in that case the OSD should be unaffected as well!? I'll see about some makeshift shielding (cardboard box+ aluminium foil?) for the board to test this hypothesis. I guess it could still be both the VGA signal and the board itself...

Deunan wrote:

henryVK wrote:

Might still be a combination of factors? or I simply need a really well made DSUB cable?

Could be an issue with the LCD driver or it's PSU as well. If the caps are failing and the power provided is noisy, it'll act up. The worse the input signal, the worse it gets. So getting the input signal to be as clean as possible is always a good thing (even if there were no other issues) but if a good quality cable is not fully fixing the problem then chances it's not the only problem you have. Oh and same goes for video cards but if you can get a stable picture on other displays and not this one then obviously it's the culprit.

Yeah, the driver board runs off the computer's PSU and the initial PSU I tested with this setup seemed to produce a lot of visible interference on my CRT even though, cosmetically speaking, the caps look just fine. Anyway, I used a way newer and supposedly decent ATX PSU and the noise cleared up a lot. I replaced the video card for one that was in better shape which reduced noise even further. I'm tempted to say that the signal is now as good as it will get, though I can't be entirely sure lacking the means (not to mention know how) to make sure the PSU and video card are 100% okay.

I could rule out the PSU by getting a 12v 2a adapter... which I was holding off on because it's exactly the opposite of what I was trying to do, running the LCD driver board off the PSU 🤣

Right-o, thanks to everyone's input I have run through some more testing.

In the meantime I tried a few more things:

• shielding the back of the lcd panel
• shielding the entire controller board
• swapping molex adapter for controller board
• switching screen resolution
• manually adjusting LCD screen phase
• dedicated DC 12V 3A PSU for controller board

None of this made a lick of difference, the noise is still there.

Now, that's not a necessarily a bad thing because it leaves a bad controller board as the likeliest culprit. Here's to the replacement board that's underway (at the cost of shipping) solving the issue so that I can put this friggin' computer together finally!

I'm pretty sure, the replacement won't make a difference.

Maybe you could elaborate on why you think it won't.

The symptoms don't seem to point towards a hardware defect. Looks much rather like it's working as intended.

I'm not sure I see what you are getting at.

Alright, alright, alright.

After testing the LCD with another controller I'm 99% sure it's the LCD display itself that is faulty, although I can't say what exactly is wrong with it. In the best case this info will help out someone in the future with the same interference issue!

While this was a somewhat drawn out process, I'm pretty happy to have finally identified the culprit and will be able to move on with this project. I got a cheap refurbished IBM-branded 10" display and controller board off eBay which works just fine. The colours are not quite as nice but the viewing angles are a lot better. Incidentally, this is the display that I originally considered getting before deciding on this Chinese TFT (I know, they are all Made in China) ... oh well!

PS: having never ordered parts from Chinese sellers I was suprised how quickly and readily they responded on eBay. One sent me a replacement with no questions asked and the other one offered a refund on the spot, no need to return the items.