Green-washed TFT monitor problem... wha?

[meerkat]

I have had one of my monitors go south recently, with a pretty bizarre problem.

First off - it's a 19" standard aspect Elonex branded Hannstar panel, about 2 years old. Using it for media center, nothing stressful. I've had replace a couple of bulging caps in the power subsystem over the past year, but that doesn't sound too relevant tbh.

The thing has come over all green. Colours are mental, washed out and... green! The weird part is, the onboard configuration menu system has a white background. Now you'd expect this to be, if it were a hardware problem, green-washed out like the picture. It's not. It's crystal clear white.

I've tried with a couple of different machines, resolutions etc. And there's no help. It's almost as if the analogue auto-configuration has become corrupted somehow and is skewing everything to the green part of the spectrum.

Is this a known problem here? Anyone had experience with, let alone fixed something like this? Can't find anything by searching, but I could be using the wrong terms.

[Agent]

The only thing I can think of is the input controller board within the TFT.

The bulging caps - were they within the TFT? i suppose there is the chance that the bad caps may have weakened other components on the PCB if it was giving out bad voltages.

Are you using D-sub or DVI? Tried swapping if it has both?

[meerkat]

The only thing I can think of is the input controller board within the TFT.

The bulging caps - were they within the TFT? i suppose there is the chance that the bad caps may have weakened other components on the PCB if it was giving out bad voltages.

Are you using D-sub or DVI? Tried swapping if it has both?

Thx for reply. Should have also mentioned for reference, it's not a loose connection on the cable. Did that already

The faulty caps were on the power PCB, the monitor has 2 distinct boards. I just had a couple of incidents of the monitor randomly shutting off to diagnose that, but you're right - dodgy voltages going through could have set the ball rolling.

Sadly this is a DSUB-only monitor, which is why it's relegated to being a glorified TV. Google pulled out a couple of instances of this happening and no resolution ("just use the other input"). I could have a look and see if there are other input headers on the PCB... seems a shame to get rid as it's still a good panel...

[Pob255]

Have you checked both end's of the cable? I ask because I've had this problem on a few old laptops and a could of pc's (on board graphics cards) useally putting pressure on the plug going into the port (bending it up slightly causes the green hue to go.
Unfortunately this is a sign of something dieing, all the laptops have totally lost d-sub out after a few of months (2-8) of first turning green.
A partial break in the cable or a bent pin can also cause this, basically it's lost feed from one of the d-sub pins which causes it to read the d-sub red and blue channels too low or the green too high (cannot remember exactly how it works)

Start with a different cable to eliminate that, then a different pc/output device to eliminate that, bend the plug back and forward a bit at the tv end to see if that's the problem.
(could be that one of the soldier joints between the socket and pcb has come lose or a physical break in the socket.
Failing that, then it's ether a break on a copper path on the pcb, one of the components on the pcb has died or when you did that solidering you accecdently shorted or broke something.

If it was bought new then your should of RMA'd it, most monitors and TV's are covered by 3 year warranties, even cheap brands.

[meerkat]

Have you checked both end's of the cable? I ask because I've had this problem on a few old laptops and a could of pc's (on board graphics cards) useally putting pressure on the plug going into the port (bending it up slightly causes the green hue to go.
Unfortunately this is a sign of something dieing, all the laptops have totally lost d-sub out after a few of months (2-8) of first turning green.

I've actually used 2 separate cables to diagnose this; however a fault in the female side of the connector on the monitor sounds more and more like a possible culprit (which would actually be good news). Otherwise I'll probably grab a dropped monitor from fleabay or something, & rip out the input board.

A partial break in the cable or a bent pin can also cause this, basically it's lost feed from one of the d-sub pins which causes it to read the d-sub red and blue channels too low or the green too high (cannot remember exactly how it works)

Interesting... it does sound far more plausible than the input processor spontaneously losing its marbles.

[Betty_Swallocks]

It does sound like a cable or connector type problem especially as the on screen configuration is ok. If you've checked the cables it could be something as simple as a dry joint on one of the circuit boards

[Agent]

Otherwise I'll probably grab a dropped monitor from fleabay or something, & rip out the input board.

Be careful doing this - many boards use different firmware versions depending on which panel they use. Even the smallest difference in a firmware may mean it doesn't work with your panel type. IT really is a pain

It does sound like a cable or connector type problem especially as the on screen configuration is ok. If you've checked the cables it could be something as simple as a dry joint on one of the circuit boards

Good point. When ROHS came into effect across Europe this was a common problem (cough *Xbox360*). Certainly one of the things to check