View Full Version : Screen has Yellow tinge

02-09-2009, 09:58 AM
Over the last few months my monitor has erratically developed a yellow tinge. I have found a good smack to the side of the monitor has fixed this however lately the smack has become less and less effective. (Perhaps this is what Sue Bradford was getting at with her anti smacking law...). Anyway I am guessing the screen is just old and had it but before I head out and get a new one I was wondering if there was anything that can be done to fix this (or even extend the life a bit longer).

02-09-2009, 10:02 AM
Is it a CRT or LCD screen?

02-09-2009, 11:48 AM
Its a CRT screen.

02-09-2009, 11:56 AM
Sounds like it's probably on the way out, have you tried degaussing it? Normally there's an option in the OSD somewhere.

Billy T
02-09-2009, 10:29 PM
It is not a degauss problem, it is lack of blue gun output. The three CRT gun colours are red, green and blue. R&G make yellow (R&B magenta & B&G cyan) so the screen is lacking blue.

Since the monitor is responsive to impact persuasion, the cause will be either a dry solder connection in the blue gun drive circuits or on the CRT base, a loose plug supplying blue drive, or possibly (but very rare) an internal fault in the CRT. It could be cheap to repair but I'd use a TV repair shop, not a computer shop as the latter tend not to know very much about what goes on under the bonnet of a monitor, and are rarely licenced to take the back off either. You have to be registered by the EWRB and hold a Practicing License to repair mains powered equipment for reward. This doesn't apply to computers themselves as everything is modular and there is no high voltage or mains connections to be made, other than by plug & socket.

Might be time to upgrade.


Billy 8-{)

02-09-2009, 10:31 PM
CRTs are cheap as chips anyways:D

03-09-2009, 07:04 PM
Billy T is correct. you have a poor connection between the blue drive
and the CRT blue gun. look for a poor joint on the tube base pcb, then
trace back and check the motherboard connection which could be
plug-in or soldered. Also check the solder pads underneath the motherboard.

I have repaired a few CRT monitors with this problem, including some which
were quite new but poorly manufactured.
The degauss circuit only operates at switch-on, so you can discount this
as a cause.

03-09-2009, 10:07 PM
It could be a faulty signal cable

Billy T
04-09-2009, 04:05 PM
It could be a faulty signal cable

Highly unlikely, that won't upset the operating conditions of the CRT drivers unless there is some very weird circuitry involved, and that is unlikely because different computers would then provide different screen tints.

Screen colour (greyscale) is totally independent of drive signals.


Billy 8-{)

04-09-2009, 05:52 PM
If there was a problem with the blue line in the signal cable this could cause the same yellow tint as well

Take your VGA connector and loosen it until it almost falls out and there is a bad connection. Watch the picture change colour.... (you may need to wobble it around a bit)

Doing the same thing with DVI produces even more interesting results :D

A bad connection in the cable somewhere could also be helped by hitting the monitor...

Though I do agree a problem with the actual gun drive etc is more likely