Had a 42" LCD TV from eBuyer, just over 3 years now. It was one of their no-name sole-supplier deals. Been very happy with it in every way.
A few months ago I went to turn it on, and it seemed the backlight didn't come on after the normal 15-20 seconds. I turned it off and on again, and it was fine.
Did the same yesterday.
Is this a hint that something is going to fail soon ? ISTM that LCD panel technology is at the mercy of the backlighting circuitry ... I know most LCD monitors/laptops that hit the scrap heap have failed backlights ...
Likely to be a fault in the switched mode power supply. Most likely to be the electrolytic capacitors on the way out. Change the lot - cheap enough and a good chance it will resolve the fault.
Yes and no.... Yes in the sense that this is a DIY group, so you get to be one ;-)
The most common backlight faults are not actually failure of the lights themselves, but a failure of the power supply for them.
Typically these are switched mode PSUs, that then have a LCD backlight driver chip to produce a HF AC waveform, that is fed through a step up transformer to provide the 600 - 800V to drive the tubes. Failed electrolytic caps are the first suspects, and the transformer the second. The former can be bought from any electronics component suppliers for pennies generally. The latter from ebay for a tenner. Sometimes ebay will also source full reconditioned PSUs for some of the more popular monitors/TVs
(there was discussion recently about doing a wiki article on fixing these sorts of things. If you fancy taking piccies as you go along, we could use yours as an example!)
Last question first, yes, but not all screens are still available and I don't think you can change the backlights on most. The backlight is just a normal daylight light and of course eventually they fail to strike and are then duff. Probably cheaper to get another telly. Brian
There was a mill owner in England at the end of the 19th century. The boiler that powered his factory broke down. Every day that passed he became increasingly worried. He was losing money and fretted constantly. He hired the best firms available to try and sort the problem but to no avail.
One afternoon a man walked in the door without an appointment.
?I hear your boiler is giving you problems?, said the unassuming man carrying a small bag.
?It is ? and what of it?, said the mill owner.
?Well, I?m here to fix it for you.?
The mill owner laughed. ?Ha. You honestly think you can do what the best minds in the land have spent weeks trying to do. Look at you. You are just one man with a small bag of tools. I really don?t think you will get far, but go ahead, I could do with some distraction.?
The mill owner walked with the man to the boiler room. There in the centre of a large room was the source of all the heartache. The big hulk of metal that should have been powering the mill through the miles of pipe-work that snaked it?s way through every inch of the factory. The sounds of clanking, hissing and knocking could be heard but the sound of idle machinery was deafening.
With an exaggerated flourish of his hand the mill owner introduced the boiler to the unassuming man and his small bag of tools. Ignoring the theatrics of the mill owner, the man produced a small rubber mallet from his bag.
Quietly and without any fussy he began tapping on the various pipes coming from the boiler. While tapping, or after tapping, he listened carefully to the language of the pipes. After about 15 minutes had passed, he walked to back to his bag and picked up a large wooden mallet.
He walked towards a complex looking section of piping and reaching up, he gave a firm and powerful thump with the mallet. The effect was immediate. Water began to flow again, steam pumped and machines started turning again.
The mill owner was overjoyed and thanked the man profusely. He was so happy that he told the man to double his usual price. The man said that wouldn?t be necessary and he would send his regular bill by post the following week.
A week passed and when the bill finally arrived the mill owner couldn?t believe what he was seeing. The bill was for £100 ? a huge amount of money at the time. He had paid similar amounts to others that tried to fix the problem. The difference was they had spent days rather than 15 minutes. This would simply not do. He instructed his secretary to write back and ask for a detailed breakdown of the bill.
The reply came soon after
For 15 minutes of tapping £1 For knowing where to tap £99
Did you see my comment higher up the thread about a component level repair entry for the wiki? ;-) (we can subtitle it "knowing where to tap" if you like)
Having stripped a few monitors I'm thinking of putting a multi-tubed fluoro light-box at the back of my telly when the backlight fails. :) That's assuming the electronic boards can be swung out of the way.
Yes good point, I think. I almost started off doing a repair (replacing a DIL chip on a 300W inverter, to drive CFLs from a leisure battery) but then Andrew (I think) pointed out that I could get 12 volt CFLs.
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