THE SCREEN OF MONITOR BECOME GREEN .
I would Suggest you don't try fixing this yourself. CRT monitors are basically the same as TV's, and TV's have enough high voltage stored in them to zap and kill, if you just touch the wrong spot. It's not enough to unplug them because they will still store the voltage in the caps. So please wait untill you really have enough training to do something like this. Unless you're 100 % aware of all the risks please don't ever touch a CRT.
Anything I tell you is for your general information, and if you still want more detailed information on how to actually do this, what does it all mean, along with all the information on the required equipment and SAFETY PRECAUTIONS, go here: http://www.repairfaq.org/
Or go to a local repair lab and have them explain to you just how dangerous it is. People who do this for a job know not to take chances or sooner or later they will be seriously hurt.
Is your screen flat green, or do you have a greenish picture?
If it all green, possibly shorted CRT driver transistor, possibly CRT HK short. Swap the green drive transistor with one of the others...if the problem stays with the green, install a heater isolation transformer, if it moves to the different color, replace the transistor. If the screen stayed green when you swapped transistors, there is almost certainly a heater-cathode short on the green cathode. Installing a heater isolation transformer may be a difficult project. The success rate though is not too bad, and a repair shop may be able to do it reasonable cheaply. Here's what you do: (read first...if you don't understand any part of it, DONT try it, because too much can go wrong)...
Measure the P-P voltage of the heater pulses.
Turn the set off. Cut the traces to the heaters on the CRT board,
leaving enough to solder to. Cut about a 3' piece of wire.
Wrap 4 turns around the flyback core, and solder the ends to the
heater pins on the CRT.
Turn the set on, and check P-P voltage again. If it's more than 20%
higher than it was, I put a small resistor (1, 2, 3.3 ohms, etc, 1 or 2 watts) in the line to get the voltage back to normal; if it's lower, add another wrap on the flyback core, and check again. If the picture needs brightening beyond what the controls can provide, I'll let the heater voltage go up to 40 or 50% higher than the original, but in these cases the CRT is on the way out, and won't last long.
When things are the way they should be, trim wires to a decent length, allowing a bit extra for sliding the board out later, and insulate all exposed wires and resistor leads.
If it's a greenish picture, Then it's the picture tube, RGB output transistors, heater to cathode short, or loose connections on the crt board.
Good luck, and take care
May 29, 2006 |
LG Studioworks 7D Monitor