View Full Version : Not exactly a TV...


Reece
08-01-2010, 05:57 PM
...but it makes pictures. My HP LCD monitor was taking a long time to start and finally quit. I went out and bought a new bigger one and got back on line, then decided to try to fix the old one to use on another computer. Many times it's a power supply issue, electrolytics.

The hardest part is figuring out how to open up the thing. There are a few screws, but then the front frame separates from the rear housing by using a couple of screwdrivers and popping it off. I used a marker to label all the plugs to be sure they went back where they should.

Sure enough, two caps had bulged and puked their little guts out, as circled in the left picture, 1000 mfd. @ 10V. RadioShack had 1000 mfd. @ 35V., a little beefier and ought to last longer, but they had to be laid over as shown at the right to fit in tight quarters. Finally, she lives again! :banana:
http://i177.photobucket.com/albums/w204/wrnewton/HP%20Monitor/HPMonitorComposite.jpg

freakaftr8
08-02-2010, 11:27 AM
Ahh yes, the ever so usual cap failure in the power board. I've been spending some time now rebuilding LCD monitors. Constantly finding bulged 10v 1000mfd and 25v 470's blown out in these things. This last week I have been repairing a 20" Dell widescreen LCD. This one acutally all PS caps and logic board caps are good. But the LCD driver board has a shorted surface mount diode block for the 12v protect caused by some a$$ running the monitor with the ground pole yanked out of the powercord and plugged in to a 2 wire extension cord. It took some surge and blew out the LCD driver board. So im testing my soldering skills on some extremely small surface mount equip. Fun. Also I just fixed a 46" Panasonic plasma for a neighbor. Blown FET transistor in the SU board (PS driver to the gas screen). That was fun as well. (NOT). THese circuit boards amaze me how tight everything is placed together. These LCD's get really hot. So hot that they should have designed a cooling fan system. But hence the cheapness, and inhibited space avaliable, no fans.

radiotvnut
08-02-2010, 12:03 PM
Yep, those boards are very miniaturized and they're only going to get smaller.

freakaftr8
08-02-2010, 12:18 PM
On a side note, CapXon are the worst of the worst caps they can put into an LCD monitor. I would reccomend Samxon AT 100c Temp rating.

ctc17
08-02-2010, 01:09 PM
Looks like a bunch of network switches I repaired. I have seen several motherboards with the same failure, 0 and car computers too.
http://boxcarcabin.com/Milan-Switch-Repair.jpg

andy
08-02-2010, 05:40 PM
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Hemingray
08-02-2010, 06:54 PM
Rubycons are also generally well made.

There's alot on this at badcaps.net.

freakaftr8
08-02-2010, 11:47 PM
I have managed to repair a MAG 17" widescreen, a 17" standard HP and a 19" HAANS G LCD with parts from a bad 17" LCD that had a bad logic board. LOL, the LCD im using has the screen from the parts monitor, the one next to me has some caps from it's PS and the one upstairs has the rest.. It's funny that even through the times, we still seem to have parts hassis around, from vintage CRT sets to new flatscreen monitors to plasma tv's.