|New LG CRT Monitor Loses Red Colour|
Any easy fix or test?
I've got a new LG Studioworks 700s CRT monitor which loses all red colour after about an hour. Switch it off, and it comes back for a brief time.
It does it when connected to a Linux or Win OS, so the fault is in the monitor itself, not the VGA.
Yes, I can ship it back to the Agent, but I live in the sticks and shipping costs an arm'n'leg, plus two weeks waiting.
Before doing that is there any home remedy, without taking the back off and invalidating the warranty?
There have been several electricity power-cuts in our region lately, and I don't have surge protection or UPS. Could that have anything to do with it?
I'm told the variations in power supply are usually lower, rather than elevated, and everthing else works fine.
What causes new CRT monitors to lose their red colour?
|What causes new CRT monitors to lose their red colour? |
How long is a piece of string?
It could be a loose connection, bad solder joint, broken wire etc. as the unit heats up expansion causes an open circuit.
If gently tapping the monitor causes the fault to appear/disappear this is the most likely cause.
Components failing as they get hot are more difficult to locate. You could try heating (wrap monitor in a blanket) and cooling blow cold air through the ventilation slots.
But be very careful CRT monitors generate internal voltages of upto 17,000 volts, which they hold for hours after the monitor is turned off!
Please don't be tempted to take the back off, get the monitor exchanged.
I don't know where you are, but in the UK, most manufacturers send you a new monitor by carrier and you just put the old one in the box and send it back. The dealers don't have anything to do with warranty repairs.
|I'm told the variations in power supply are usually lower, rather than elevated, and everthing else works fine. |
High voltage surges are more common than low voltage, do your light bulbs ever glow brighter or darker?
Surges are more likely to damage the power supply in your monitor than cause the fault you describe.
By the way, it's always a good idea to unplug electronic equipment when the power goes off and plug it back in when the power is restored. The surge when the electricity supply comes back on is a real killer!
I'm near Burma, and simply shipping the monitor back to the supplier costs a small fortune, plus an 8 hour bumpy bus journey to get it to the shipping agent.
See why I posted here first? :)
Yes, I know the dangers of fiddling with monitors, and you're right to stress that aspect.
I did try blowing a cooling fan on it, and it only had a marginal effect, looks more serious than a loose wire.
The suppliers carefully hide their email address, but I did manage to find it and appeal for help. The MD has agreed to exchange it if I can get it to a shop that is only an hours bumpy bus journey away.
Quite a favour. I'm impressed.
We do get frequent power surges and blackouts, especially now at the start of the monsoon season.
I do have a fuse protector, but no surge protector.
I'll be sure to pull the plug next time it looks like a power failure is on the cards.
Where I used to live, the Johnny with his hand on the Big Red button, used to warn punters of a coming blackout by throwing the switch off for five seconds, then on again for two minutes to give you chance to find the candles and paraffin lamp. Then ZAP: for hours on end.
I do also live in the shadow of a Microwave pylon 50 metres away. Could that have anything to do with it.
If it was due to power surges, wouldn't it have blasted my external modem first? That's working fine.
Yes - don't take the back off.
I used to work for Samsung and saw someone who touched (he actually got about an inch away) the cable on the back. He shot back and bounced off the next production line and shook around the floor for quite some time.
It took almost 6 weeks before he could move that arm again - so I wouldn't try it if I were you!
|If it was due to power surges, wouldn't it have blasted my external modem first? |
Modems tend to be killed by surges through the phone line, lightening strikes etc.
|I do also live in the shadow of a Microwave pylon 50 metres away. Could that have anything to do with it. |
No, but it's probably not doing your health much good!
|I do have a fuse protector, but no surge protector |
A surge protector is always a good idea, but you pay for what you get. I like Belkin ones, they guarantee to replace damaged hardware if the protector fails, their better ones even have a connection for the phone line.
|I used to work for Samsung and saw someone who touched (he actually got about an inch away) the cable on the back |
We had an 'engineer' who came to us on a weeks trial. He was given a television to repair, he decided the line output transformer was faulty (this steps 110 volts upto 22,000 volts to feed the CRT). He carefully unsoldered it , removed the connection to the tube and flew 6 feet across the workshop, much to the amusement of everyone there.
He didn't know you should discharge the LOPT first, and none of the engineers looking on warned him!
He didn't take the job, he decided TV repairs were not for him!
OK Back to topic: I need serious help here.
I've just replaced the monitor with a brand NEW one, plugged it into my computer, and blow me STILL no red colour.
I tested the new monitor in the shop, and it was fine.
So it can't be the monitor!
Now get this: I've got two computers, one windows 98, the other Linux Mdk, and the new monitor has no red when plugged into either box?!
Just like the one I took back to the shop for replacement.
So what is the problem?
Both boxes were working fine, I haven't opened either up, or changed anything. Then one day the red disappears. I switch to the other box, it's OK for a while then it loses the red too.
I thought it was the monitor, but it's not.
C'mon you experts, what's going on here?
I tried resetting the Win display to 16 bit, then to 256 colours, then back to 16bit. But no change.
The screen is blue and yellowish, and red shows as black.
Just floating an idea: You mentioned that you have power surges and spikes, could you also be experiencing the opposite, brown outs? Perhaps the monitor does not like the power feed?
Well, to check that I could take the new monitor to a neighbour's 'puter, but it seems unlikely to be a brown out, lasting days on end.
Everything else is working fine, lights not flickering.
Could it be anything to do with the VGA card?
But it would be very odd for the VGA cards in two different computers to have the same problem at the same time wouldn't it? Both computers have been OK for months, now neither displays red colour from startup.
Looked like the monitor was bust, > NEW monitor, same problem?
Is the monitor signal lead the same?
What I'm trying to get at is it hardwired into the monitor or detachable? Could it be damaged?
Is it possible something else in the room or area is causing interference? Does the fault occur when the fridge, air conditioner, or arc welder your next door neighbour just bought turn on?
Try moving to another room, keep all your cables phsically seperated. Does this help?
How hot is your room, if its much hotter than the shop is overheating a possibility?
Thanks for your suggestions Steve.
As a test, I took my new LG monitor to my friends cybercafe and plugged it into one of his machines.
So it clearly is the same fault on two NEW LG Studioworks 700s monitors.
I've emailed the manufacturer to ask them to change it again.
It'll be the last LG monitor I ever buy.
Asking around, I hear LG have a bad reputation for quality control.
You have been warned. :)