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I found an LCD flatscreen monitor on the sidewalk. Took it back to the lab, turned out the screen was pretty dark, especially on the bottom half, so I figured the backlight was broken. I opened it up and found this to be true. turns out one of the two outputs of the power inverter that fed the two backlights was broken. I had a set of CCFT lamps + inverter ($15--> http://www.allelectronics.com/cgi-bin/item/FL-122WH/search/SET_OF_2_CCFT_LAMPS_(WHITE)_W_INVERTER_.html) lying around from a previous project (lighting a sound proof temperature controlled experimental box) so I decided to pop one in. Here's how I did it (it worked great).
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Signing UpStep 1Open it up carefully
FIRST OF ALL, BE VERY CAREFUL, THE CCFT LAMPS CONTAIN MERCURY GAS WHICH IS VERY POISONOUS. I take no responsibility if you are in any way injured by mercury gas or any other procedure described in this instructable. To be safe you should do this outdoors or in a very well ventilated area in case the lamps break.
having said that, open the monitor carefully. There will probably be at least two or three weird overlapping wire connections (see picture) which you'll have to carefully unplug to get everything apart. Inside you'll find the LCD screen, a thick glass/plastic light diffusion panel, some thin plastic light diffusion sheets, and two CCFT (cold cathode flourescent lamps)backlights (at the top and bottom of the LCD screen).
Figure out which lamp doesn't work. This may be because the lamp itself is dead, or because an inverter output is dead (the lamps use AC which is converted via an inverter from the DC sent to the monitor). These lamps take high voltages, if you plug in the monitor to figure out if the lamp is broken be careful.
having said that, open the monitor carefully. There will probably be at least two or three weird overlapping wire connections (see picture) which you'll have to carefully unplug to get everything apart. Inside you'll find the LCD screen, a thick glass/plastic light diffusion panel, some thin plastic light diffusion sheets, and two CCFT (cold cathode flourescent lamps)backlights (at the top and bottom of the LCD screen).
Figure out which lamp doesn't work. This may be because the lamp itself is dead, or because an inverter output is dead (the lamps use AC which is converted via an inverter from the DC sent to the monitor). These lamps take high voltages, if you plug in the monitor to figure out if the lamp is broken be careful.
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I'm an electronics engineer. I've spent 5 hours repairing a $3 transistor radio many times. It's not the money (well, not always). It's a challenge, a game. And when I go through the radio (or??), I make improvements. First, I "bullet proof" (replace/modify parts/circuits most likely to fail). I'll replace an IF transformer with a ceramic filter, improving selectivity and fidelity. I use larger interstage caps and rebias sections that are distorting. I might add a 3 watt mono class D power amp, power it with D cells or a 6 volt 7 amp hour gel cell, add a charging circuit that won't fry the battery, and mount it all inside a nice speaker cab. I *hate* those little tiny tuning wheels and usually replace them with vernier knobs. These are very accurate, and eliminate the need for digital displays. I snap up vernier dials for pennies on the dollar at ham swap meets, estate sales, and such. Some of these are 30:1, and built like They're too expensive (new) for consumer gear. They're fairly routine on lab gear and military electronics. I *LOVE* JAN (joint Army-Navy) and MIL SPEC surplus.
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http://www.instructables.com/id/Replace-LCD-Backlight-Inverter-on-Any-Monitor-for--
Hmm I may try this.....
Also can be seen here:
http://www.inventgeek.com/Projects/shorts/lcdfix.aspx