Does a backlight "die" completely?

Hello all,

Can anyone tell me if a laptop's CCFL backlight is like a household lightbulb - that is one it has "popped" it is physically broken and will not work again?

The reason i ask is that the screen recently died on my 3 year old Acer laptop, however when i shine a torch on the screen a faint image does appear (I've currently hooked it up to my desktop monitor). After investiagtion, it seems to be either the inverter or backlight has died, i've replaced the inverter but with no joy.

I tried lowering the screen brightness to see if that helped and after reducing to 20%, the screen suddenly relit and has been on fo the last half hour. If i turn the brightness any higher the screen stays on for a few seconds before returning to near darkness.

Any comments or advice regarding solutions i may want to try?

 

A CCFL backlight is more or less like a small florescent light bulb. Once it's dead, it's indeed dead.

 

the problem description smells to me like a bad inverter board. Replacements are cheap and easily found on ebay.

 

thanks for the replies, i've already replaced the inverter board with one bought from ebay (albiet used but the compnay states it is in working condition).

It seems odd that lowering the brightness allows the screen to work. Does anyone have any suggestions?

EDIT: Forgot to add, its an Acer 3692 if that helps...

 

I think its the backlight. The faint image and screen coming on at low brightness levels are classic backlight fail symptoms.

One soln would be to buy a used LCD off ebay and use that.

 

If you actually take the inverter board off, look for a small blue chip. It will be labeled CX X being any number 0-9
You can remove it and solder a replacement fuse in replacement of the blue chip. You can use any fuse you like, but its best to use one less than 1 amp

K-TRON

 

thanks for all the replies, i've ordered a new CCFL tube so i'll post back if that works...

 

Wow, you must be skilled, I hear replacing the CCFL is a hairy job which requires tons of patience and delicate handling

 

No scratches or fingerprints on the ccfl. Use medical-grade alcohol wipes to clean both your hands/fingers *and* the tube. Scratches and skin oils will cause hot spots on the tube which will lead to a very short life or possibly the tube breaking open inside of your machine.

A ccfl contains just enough mercury to make it hazardous waste. be careful out there.

 

Agreed, with one cavet. Even though your hands may be clean, I would advise wearing disposable cotton gloves (often they are included with the bulb).

This site has a guide for replacing the ccfl http://www.laptoprepair101.com/laptop/2007/12/09/replace-laptop-backlight-ccfl-lamp/

Definately not an easy task!

 

Well I bought a new ccfl tube with new connectors (which i had to resolder myself as they came unsoldered). I hooked it up to my inverter board just to check it worked before I took the screen apart (it did!). It was frustrating and quite fiddly but I did eventually manage to route the ccfl wire along the guide, I reassembled the screen the screen (there's always one screw left over...) and started up - it didn’t work...

The screen is a little brighter but still black even when selecting full brightness via the power management. I had another go today and everything appears to be in the right place (but obviously not). Altogether it was at least a learning experience.

I'm ordering a new Acer 5738Z - this has an LED backlight to see if it lasts any longer. I'm keeping the old Acer anyway so I’ll maybe go back to it again at a later date and have another go