replacing/repairing backlights on lcds... ? :D

[ZippyDan]

im wondering if its possible, or more specifically, reasonably feasible, to replace dead backlights on LCD screens. i guess this means:

1. do most LCD screens use some standard form or forms of backlights (shape, size, brightness, power, etc), or is it all proprietary per brand per model?
2. keeping in mind 1. are replacements easily available in general, or are they more available for some models than others, or not at all?
3. assuming a reasonable proficiency with internal computer components and soldering skills, is it straightforward to perform the actual replacement work?
4. are replacement backlights reasonably priced?
5. if the backlight itself is usually not the culprit, but some other part usually is (inverter?), then replace backlight with said part in all questions above

the reason i ask this is because 1. im starting to invest more in upgrading my fleet of CRTs to LCDs, and 2. i have seen LOTS of dead backlights on LCD monitors both standalone and on laptops, so im worried about that. and 3. the thought of working on the inside of an LCD is much less intimidating than the trepidation i always felt when working on the internals of a CRT

~Zippy!

 

[DanDaMan315]

Back lights are rated from 30,000-50,000 hours - so the time between burnouts is few and far between. Can't CRTs burnout too? I don't know how long the life is on a CRT but I'm pretty sure they can burn out too.

 

[ZippyDan]

then all the dead backlights ive seen mustve been caused by something dying other than the backlight itself. something that supplies power to the backlights. for some reaosn i think what tends to die most commonly is called an inverter

 

[ZippyDan]

MAYBE?

 

[IGBT]

..I have 5 flat panels from 15" to 19" and none of the back lamps have failed..one of them is a 15" Prinston (sp) thats 5 years old..on all the time and still works/looks fine. I hear some mfgr's build the lamps into tha panel glass and aren't replaceable. Got to R/R the whole glass assy..would be cheaper to just buy another display.

 

[jfrog]

Well, someone gave me a LCD monitor with a dead backlight. Found out the inverter that runs the CCFL's died(inverters usually die more often than the CCFL tubes themselves). I bought some case modding CCFL's, took the inverters from those, and hacked them into the dead LCD. I'm typing on this LCD I fixed right now. Only problem is the backlight always stays on now, so I just unplug the monitor to turn it off.

 

[sharkeeper]

Most TFT BL failures are due to the inverter experiencing an anomaly where the tube is fine. Abuse (dropping, smacking, etc.) can cause the tube to crack and this type of handling is apparent immediately upon inspection.

EOL is determined when output reaches 50pct of original. It's possible to use considerably longer than this.

Sometimes a fuse will open up killing the backlight.

It is not recommended to service these products without proper training.

 

[ZippyDan]

ok so we've confirmed its the inverter that most often fails

1. do most LCD screens use standard inverters, or is it all proprietary per brand per model?
2. keeping in mind 1. are replacements easily available in general, or are they more available for some models than others, or not at all?
3. assuming a reasonable proficiency with internal computer components and soldering skills, is it straightforward to perform the actual replacement work?
4. are replacement inverters reasonably priced?

anyone?

also, whats wrong with servicing it without proper training? no exploding vacuum tubes here. probably some capacitors retaining charge. anything else to worry about? if the unit is already broken, no point worrying about breaking it more. and the professional repair costs for these things is usually more than its worth to buy a new one... so cant hurt to try and repair it urself on the cheap

 

[sharkeeper]

Dismissing the obvious hazards present, non qualified service usually results in a product with subpar performance including repeated failure. The correct tools are mandatory. Inverters should be replaced with correct mfr part numbers always!

 

[ZippyDan]

sigh i dont mean to be disrespectful cuz u r obviously trying to be helpful, but you sound like a computer tech at compusa talking to a grandmother about why they shouldnt try to replace a hard drive on their own because it might be dangerous

this is anandtech, we're supposed to tinker with stuff that most people wouldnt want to

as i indicated, assuming a backlight fails, im not interested in "qualified" service because it usually is not justified versus the cost of simply buying an all new unit. IF all that needs is an inverter for instance, i dont see how hard it could be to desolder the broken one and resolder a new one. what about that will result in subpar performance?

finally your comment that inverters should only be replaced with mfr part numbers (or equivalents) gets a duh from me. obviously you want to repair it with the right part, and not a scavenged part as jfrog describes above (and his backlights not turning off are the subpar performance result of that). one of my questions was indeed, how hard is it to acquire the CORRECT parts to repair an LCD?

thanks for your help

~Zippy!