Wednesday, February 18, 2009

Fixing LCD Monitor

Few weeks ago, my sister-in-law asked me to fix her LCD monitor, which became dark, very dark when turned on. It's a 19" Westinghouse model L1975NW. I took the back off, and notice the board has few components which responsible to drive the back-light of an LCD screen. After tracing out the circuit, and identify failed components (a surface mounted fuse) I went ahead order parts at Mouser Electronics. Even though only the fuse is definitely failed, I also order new FET & capacitor, just because I have no way to test them. While waiting for the parts to arrive, I removed the FET, capacitor & the surface mounted fuse. Few days later the parts arrived, I soldered them on the board and very happy that the monitor is now fixed. If there are anyone interested, I'll post the part lists & locations of them on the board.

Here is the picture of the power board, with the FETs circled. Unfortunately, I did not take the picture of the other side, where the surface-mounted fuse resided. After removed these components & replaced with new ones, the monitor works again. BTW, when I order the FETs, I also ordered the clip on heat-sinks for them, I believe that these FETs were driven so hard & so with the heat sinks they will certainly help prolong the life of the new FETs.

Here are the list of parts that I ordered:
  1. Qty of 2, FETs
  2. Qty of 2, TO-220 heat sinks
  3. Qty of 1, fuse
Removal of the FETs was not that bad, but soldering the surface mounted fuse was a bit difficult. My eyes aren't as good as they used to be, so I need a magnify glass to perform this task.

Also, correction: I also ordered the capacitors, however I did not replace them, for I believed replacing the FETs & fuse would be sufficed, and indeed they do. So, after replaced the FETs & fuse, I put them back together and the monitor is revived.

Empty lot

The demolition company took a bit more than 3 days to bring the whole house down, flatten the lot, took out few trees and prep the place for it ready to build a new house on top.

Every day, we drive by the lot, anxious & curious of the development. So, when we pick up Thuy. from the Williamsburg Middle School, we swing by the lot & look. We were fascinated with the front-loader & workers busy bringing the house down & taking load after load of debris out of the lot. The house once was there, now no more. It's an empty lot, ready for something new, something we are going to call "home".