LG Flatron L1932TQ won't turn on
I have the exact same problem. Just like Ptepe, I also found the 680uf/25v and 1000uf/16v capacitors in positions c203 and c204 on the Power Supply PCB to be bulging on the top. I considered replacing all of the electrolytic capacitors on the board, but decided to just try the visibly effected ones first. Please make note that the instructions provided below are to be followed at your own risk! Soldering on a delicate printed circuit board will be required for this repair and the board can be permanently damaged if done incorrectly, not to mention the potential for bodily harm! If you have warranty, you will obviously want to pursue that avenue first.
1) Remove the monitor's base by removing the plastic cover over the connectors and then the one over the base's bracket and unscrewing the four screws. While you're in the area, there are two screws, one on either side of the bracket, that must be removed. They are in the recessed wells.
2) Turn the monitor upside down so the narrow edge is facing you. You will see at either end of the bottom edge an arrow pointing toward a slot. Side a small flat head screwdriver under the cover in the direction of the arrow. With the screwdriver still inserted, unclip the bezel by pulling the plastic in the direction of the arrow. Repeat on the other side and carefully pry the rest of the clip points loose all the way around the screen, while carefully holding pressure against the screen so it doesn't fall out, and the plastic bezel will come off. Be sure to unscrew the switch assembly from the bottom. There are two screws.
3) Lay the monitor face-down on a soft, clean surface like a folded blanket. There will be five screws on the back with the fifth one in the center. Remove all of these screws and very gently lift the plastic cover away, making sure to keep the screen from falling out abruptly.
4) With the back of the screen and electronics exposed, you will see a sheet metal case with a few wires routing from it to three points on the monitor and the switch assembly. To the left you will see a metal cover held in by one small screw on the narrow edge. Remove this small screw and partially remove any tape that may be securing it. You may replace the tape later if it loses adhesion. Remove it, gently lifting the metal case where it overlaps the cover.
5) Next, partially remove any tape that is securing the wiring harnesses (it can be completely removed if you are planning to replace it). This will give the metal case a sufficient range of motion to allow you to lift it up on the right edge and expose the large harness routed to the top of the screen. This harness has a bit of tape covering the connector at which it terminates, and the tape must be lifted to expose the connector. Gently remove the connector straight out of the socket. Avoid diagonal movement as much as possible.
6) With the large connector removed, the metal case can now be flipped over, with the screen remaining flat, to expose the circuit boards it houses. On the left is the processor board, on the right (the one with the big capacitors) is the power supply board. First, remove the black plastic cover over the power supply board. This may require some flexing of the plastic and/or clips. Be sure to make sure any wires attached to it are detached. Next remove the small metal slide panels covering the upper and lower wiring harness connectors on the case (the ones routed to the upper and lower parts of the monitor on the left side). With the two upper and two lower connectors exposed, note their positions and disconnect them.
7) Now the case is completely disconnected from the monitor. Carefully remove the connector from the board on the right that connects to the board on the left. Unscrew the four bolts holding in the power supply board (the lower left screw is larger than the others). Carefully lift the board out, angling the side with the power connector downward. Be very careful not to touch components on the circuit board.
8) By comparison, you may clearly see which capacitors are bulging on the top. These are the ones you want to replace. If mine and Ptepe's experiences are consistent with yours, you will see two out of a cluster of six larger capacitors with bulging tops (the cluster is on the opposite side of the really big capacitor and the two common capacitors are surrounded by the others). While you have the board out anyway, check for continuity through the fuse with a Digital Multimeter and check for any visible defects such as burn marks or melted solder points.
9) Very carefully desolder the effected capacitors. Verify their rating (most likely one 680uf/25v and one 1000uf/16v capacitor) and order them. If you'd like to replace all of the medium capacitors, it couldn't hurt. You can even replace the really big one if you want, but make sure you measure everything...including height, width and terminal spacing. For the ones that I used, though, they're 10mm x 20mm radial aluminum electrolytic capacitors with 5mm terminal spacing and 105C temperature rating.
10) Solder in the new capacitors, clip the excess pin lengths and reassemble in reverse order. It may take some finesse to put everything back the way you found it, but if you paid attention while you were taking it apart, it shouldn't be too hard (and taking pictures with your camera phone along the way can help too).
This solution worked for me. If it wasn't for shipping, I would have paid $1.18 for the entire repair. If you can find it, the power board can be replaced as an assembly, too, if you screw it up. :) Good luck!
on Oct 04, 2014