How do LCD's die?

[Dave Sell]

I don't have much personal experience with LCDs as I've used CRTs exclusively at home up till a month ago, so I don't know how LCDs normally die.

The reason I ask, is we have like 12 "dead" LCDs here at the office, but they all exhibit the same wierd behavior.

You can plug them in and hook them up and turn them on, but the screen will only be "on" for a split second; then they go completely dark. Even the menu buttons don't show up so they are effectively dead.

Is this normal, or am I doing it wrong, because I am getting ready to junk the whole batch.

THanks!

Dave

[techgnome]

I'm assuming that "hook them up" means also hooking them up to a viable signal (ie, a computer... and one that isn't in sleep mode)... as most will go into power save mode when it loses the video signal.

It's possible that the LCD itself is OK (since you did say that they do come on for a moment)... it maybe a short that is causing the problem, or a broken power switch... does the power indicator light up at all? Usually though, they can last several years, and when LCDs go bad, they go bad once pixel at a time (in other words, specific LDCs themselves will go bad, not the whole monitor all at once).

what you may want to do is call around, see how much some one will charge to take a look at it... or if it's old enough, toss them out (be responsible, find a recycler... heck, see if someone will be willing to give you a discount on new ones if you turn in the bad ones to be recycled... they're going to make a bunch of money anyways since you'll be replacing so many).

-tg

[Dave Sell]

We have a branch in South America where we send all our "dead" PC hardware too.

I have used various power cables, and yes hooking them up = connecting VGA to a live PC.

Just seems very odd and coincidental that all my dead monitors do the exact same thing - all different brands like Acer, Dell, etc...

[techgnome]

I'd take a sampling to a tech and see if there's something else wrong... could it be the PC you are hooking them up to?

-tg

[Dave Sell]

tried on multiple PCs

[techgnome]

Well, sheee-ooot... does seem mightily suspicious... I'd have a sampling checked out... then tossed if they can't be easily/cheaply fixed.

-tg

[CVMichael]

I work in a company with at least 200 computers, all the LCDs work fine.

I use LCDs at home for like 5 years (I think, or is it more than that ? hmm), and they still work fine... (first one I bought was like $600...)

[EntityX]

Just seems very odd and coincidental that all my dead monitors do the exact same thing - all different brands like Acer, Dell, etc...

The answer to your problem is very simple. You have an LCD demon infestation at your office. You must call a qualified LCD demon remover. If they don't have the proper credentials you very likely will be dissatisfied with their work.

[techgnome]

I didn't think of that... maybe the problem is that he's got eels in his LCDs...


-tg

[Dave Sell]

The answer to your problem is very simple. You have an LCD demon infestation at your office. You must call a qualified LCD demon remover. If they don't have the proper credentials you very likely will be dissatisfied with their work.

Is this related to my Haunted Mousewheels?

[techgnome]

Could be... sounds like the spirits from the mice have moved into the LCD monitors... have you tried an exorcism? Or you could try calling the GhostBusters.

-tg

[baja_yu]

[dilettante]

Probably bad backlights if so many act the same way.

I've seen a similar symptom with a bad power supply, but it was an isolated case.

All but certain newer models and some small models use a flourescent backlight tube. LEDs are becoming more common now though.

[Dave Sell]

Probably bad backlights if so many act the same way.

I've seen a similar symptom with a bad power supply, but it was an isolated case.

All but certain newer models and some small models use a flourescent backlight tube. LEDs are becoming more common now though.

Can't blame the power supply cause they all use 120V AC straight from the wall, but ya that fluorescent backlight sounds like it could be a culprit.

[stanav]

Most common problem with LCD monitors are dead power supplies. While some LCD monitors come with a brick style PS, most these day have a PS built in (and that's why you can plug it directly to a wall outlet). If you disassemble one, you'll find that the PS is on its own circuit board and the most likely reason for the PS to go bad is one or more bad capacities. You can replace those caps with ones that have the same specs from any electronic stores (radioshack for example), but before doing this, ask yourself if it worth it. You may find yourself wasting many hours disassembling one, replacing the blew caps, putting the thing back together and it still doesn't work afterward...

[Dave Sell]

Most common problem with LCD monitors are dead power supplies. While some LCD monitors come with a brick style PS, most these day have a PS built in (and that's why you can plug it directly to a wall outlet). If you disassemble one, you'll find that the PS is on its own circuit board and the most likely reason for the PS to go bad is one or more bad capacities. You can replace those caps with ones that have the same specs from any electronic stores (radioshack for example), but before doing this, ask yourself if it worth it. You may find yourself wasting many hours disassembling one, replacing the blew caps, putting the thing back together and it still doesn't work afterward...

On-board power converters... Didn't think of that! I wonder though, the screens power up for a split-second and then go dark. Is this a common failure behavior for failing power converters? I like your idea of replacing the capacitors, too. Don't think I will mess with that!

[dbasnett]

I don't have much personal experience with LCDs as I've used CRTs exclusively at home up till a month ago, so I don't know how LCDs normally die.

The reason I ask, is we have like 12 "dead" LCDs here at the office, but they all exhibit the same wierd behavior.

You can plug them in and hook them up and turn them on, but the screen will only be "on" for a split second; then they go completely dark. Even the menu buttons don't show up so they are effectively dead.

Is this normal, or am I doing it wrong, because I am getting ready to junk the whole batch.

THanks!

Dave

Did they ever work? Take one of the bad ones to a single family home and try it.

[yarnim]

surprising how many people have completely no idea besides a few.

Stanav said it, but it definitely is the onboard power board that went bad. This is awfully common on them LCDs with the powerboard built in. Bad capacitors on the power board is almost always the problem for the monitor symptoms you have described. I am 99% sure.

[baja_yu]

You know what's also awfully common? Newbies answering old/dead threads. But this one is just under a year old which is quite good, so congrats!