Advice sought on repairing LCD Monitor

OK, my company was throwing away a ViewSonice VG191B 19" LCD monitor because it was broken and out of warranty. I’d guess it’s about 3 years old.

So, I asked if I could have it, and they said I could. I took it home, and it behaves as if it’s not getting a signal (that is, the screen shows the same content whether the cable is plugged in or not). I tested the cable, and it’s good.

So my question is: can you do a likely diagnosis from this much information and tell me if getting an estimate for repair is worth it? I am assuming (I haven’t tried yet) that if I take it somewhere for an estimate and the amount is too much so that I don’t get it fixed, they will charge me some fee for the estimate.

Anyone have any experience in this area? I know I can buy a new monitor this size (and lighter in weight) for anywhere from $300 on up, but this was a pretty good model in its day and if I can repair it for $100-$150, I’d be ahead of the game.



Gateway quoted $500 to repair the backlight on a laptop LCD, so I’d expect the bill to be stiff.

What do you mean by “the screen shows the same content whether the cable is plugged in or not”?

Are you getting nothing or are you getting a display from the monitor itself on the screen?

If you ARE getting something on the screen then it could just be a connection problem. Sometimes you’ll get bad or broken solder points on the jack you plug the cable into. Try plugging the cable in, turning the computer on, then gently (but firmly) move the cable plug around. See if you can get any kind of a connection. If you can, you’re in luck. That’s a fairly simple fix and shouldn’t cost much.

If you are getting nothing except for some light shadow images that is often a bad or dead backlight. Bad back lights are spendy new but sometimes you can find a replacement from an LCD that has a broken panel.

The other thing you could do it carefully pull the LCD panel from the case, remove the backlight and mount the LCD panel to a window using sticky tape. :slight_smile:

Or make a LCD projector.

Thanks I should have been more specific. I am getting a red background with a floating test pattern with different colors. So the backlight is ok, and the individual LCDs look ok as far as I can see.

I will try your test.


No glory from the test. THis time after turning on the power the background is black, and the floating test pattern says “no signal”. Then after a bit it says “Testing…” again, although the background stays black. No idea why it was red earlier. The screen itself still looks good.

There is another connector I might try, if I had a cable. It has 24 pin holes in 3 rows, in a rectangular pattern, with a long slot to one end of it. Sort of like this:

         . . . . . . . .
         . . . . . . . .    __
         . . . . . . . . 

(The proportions are distorted on preview because the extra spaces are being deleted, but this is the general arrangement). If someone can tell me what kind of connector that is, I can maybe spring for a cable of that type…



That is a DVI connector.

I’m looking at the webpage for that monitor and it looks like it has both a DVI and a DB15 connector.

You can get a DVI to DB15 cable or a DVI cable and use an adapter to get you to DB15.

I’m kind of wondeirng though,. can you pull up the monitor’s on screen menu? I’m wondering if this monitor has a selector for your input type. If you’re trying to connect using a DB15, try getting into the monitor’s settings and see if there is a setting for input type: analog | digital. Try changing it to analog.

Most LCD’s I’ve seen with real problems won’t display anything. The fact you’re getting a “no signal” message is a good sign.

Also, that monitor’s best display will be 1280x1024. I don’t know what the resolution and refresh rates are on the computer you’re hooking this up to, but while you’re playing with the monitor set the computer to display 800x600. At least that way you’ll know you’re sending the monitor something it can handle.

Even more than CRTs, LCD monitors are generally not worth fixing out of warranty unless they’re some high end unit. If you knew the unit inside & out it may well be some $ 10 part, but paying some one to diagnose that & install the part will go a very long way toward buying a new 19" LCD.

Trash it.

Can you get the built-in configuration menu to appear? (assuming it has one) It may be that for some reason it is looking for a signal on the wrong input connector, although these things are usually auto-detecting.

How and when did it fail? Was it found not to be working one morning, or did it stop working in active service?
I ask because I had a situation like this where a flat screen wasn’t working one morning and on investigation, one of the pins inside the cable connector was bent right over; turns out it hadn’t just failed, but the one of the cleaning staff had tripped over the cable and sent the thing flying across the room. I gave up trying to fix it as soon as this fact emerged.

No, none of the buttons on the front produces any effect (except the power button) so I can’t get into the configuration menu. I already examined the pins in the connector, they are all fine.

I don’t know the history of the piece, it was just in a pile of stuff the company was discarding and offering to anyone who wanted it.

Thanks for the advice and information, folks. I think I’ll risk the cost of a DVI cable or converter, if it’s not too much, and see what happens.


For those who are following this breathlessly:

I have carefully opened up the back of the monitor, and there are no obvious loose connections. The input connectors appear to be integrated into a circuit board, and I don’t have any way of testing that. So I put it carefully back. I might have to replace the circuit board, and I don’t know how much that would be.

My video card is an ATI 9600 series, and to remind myself I looked them up on the internet. It says it has three types of connectors: VGA (which is the usual DB25 female connector), TV (which is a coaxial connector) and DVI - which is not anything like the DVI connectors or cables I have seen. It is nearly square, with one corner knocked off, and as near as I can count there are 29 pins - a 5x5 square and another row of 4 additional pins near the knocked-off corner. Something like this:

. . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
Anyone know what kind of connector that is called?