The transformer seems to be the most common problem. I've only tried
to repair about 4 of these. Three were visibly (under a microsocope)
burned and probably shorted when the insulation melted between turns.
One was open. All were repaired by replacing the transformer (usually
cannibalized from a similar LCD inverter). I've also seen a few with fried switching transistors. However, those
were probalby the result of a shorted transformer.Only once have I seen a dead CCFL tube (that wasn't broken by whomever
tried to repair it previously).At this time, I don't consider it worth the time and effort to repair
the inverters. I might if I can't obtain a pull-out repacement on
eBay or if the LCD inverter circuitry was built onto the main driver
board, as is common on many LCD computah monitors. Incidentally, I've been tempted to slop some thermally conductive
epoxy on the xformer in order to improve the heat dissipation.
However, without an IR camera, and more spare time, I haven't
bothered.
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D
Santa Cruz CA 95060
Skype: JeffLiebermann AE6KS 831-336-2558
The Westinghouse L1975NW monitors seem to have a common failure point and this Instructable will show you have to repair this problem. If your monitor has either a blinking power LED or no power at all then this should be the solution to get it back up and running. To complete this repair you will need the following:
Tools:Phillips screwdriver, flat blade screwdriver, soldering iron, de-solder braid and a pair of tweezers.
Parts: Qty 2 40T03GP MOSFET, Qty 2 220mf 25v capacitor, 1 4amp pico fuse (surface mount)
We have a kit of all parts needed on our web site -la.com/catalog/product_info.php?cPath=21_35&products_id=28
If you don't have a monitor to repair check Ebay.com, you will find them for sale usually for less than $30 in as-is condition, just be sure the screen is not cracked.
This repair guide also works for the Acer AL1916 and the Gateway Gateway FPD-1830 as these are the same monitor on the inside.
First we need to remove the back cover. You can start by removing the stand, pull the little cover off the screws and remove the 4 screws under the cover. Next remover the signal cable. Now remove the 4 screws one in each corner as shown in the photos. The next step is separating the two halves of the case. Start on the side of the screen and insert the flat blade screwdriver between the front and back halves. If you apply a little pressure with the case should separate a little bit, now just work your way around the monitor. When you get to the bottom you will need to unplug the two speakers from the control board before the case will separate.
Now that the plastics have been removed we need to get to the power supply board. Turn the monitor over face down. Remove the ten screws and nuts as indicated by the yellow arrows, and unplug the backlight tubes - red arrows and remove the metal shield. You will see the power board on the left and the driver board on the right. Unscrew the power supply board and remove it from the reset of the unit.
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