I’ve been happily using a Dell LCD monitor for a few years now, but  it eventually  began doing a bit of an electronic opossum impression,  playing dead when I hit the power button. Often I could coax it back to  life if I “tried turning it off and on again”  by completely switching off the power bar, waiting a minute, and  powering it up. However, even that eventually stopped working, and I  conceded that the monitor was dead, dead, dead.
At that point, I was resigned to shipping the dead monitor off to the  electronics recycling depot in the sky, but a GeekFriend suggested that  I first take a look at the power supply. Apparently these monitors are  well known for dying when the capacitors go bad, and it’s fairly easy to  replace them. With nothing really to lose, I opened it up and took a  look:

The power supply circuit board (photo by Roy Wood)
A quick peek at the power supply circuit board and it was obvious  that one of the capacitors was, indeed, bulging and likely defective. As  capacitors age, the electrolyte breaks down and hydrogen gas is  released, causing the metal can to expand and bulge upward. If the  pressure becomes great enough, the can will burst, leaking electrolyte  all over the circuit board and possibly causing even further damage. In  my case, it was just bulging a little and failing to store charge as  required.

Bad cap!  No donut!  (photo by Roy Wood)
Once the bad cap was identified, it was easy to desolder it and get  ready to replace it. As you can see, the polarity of the capacitor was  clearly marked on the circuit board:

Circuit board with capacitor removed (photo by Roy Wood)
With the bad capacitor removed, it was easy to identify the  electrical characteristics and find a suitable replacement. My bad cap  was a 1000uF device, rated for 16V. I didn’t have an exact match on  hand, but I did have another 1000uF capacitor rated for 20V, which was  fine. Soldering the replacement into place was quick and easy.

It's soldering time! (photo by Roy Wood)
Once the bad cap was replaced and the monitor reassembled, it was  time for the moment of truth. I held my breath, plugged it in, and hit  the power button. Thankfully, rather than an electrolytic bang and cloud  of magic smoke, I saw this:

It's alive!  (photo by Roy Wood)
I’m pleased to report that surgery was a complete success and the  patient is now fully recovered. No more playing possum for this monitor.
Now, is this kind of repair something that every GeekDad reader is  going to be comfortable performing? Probably not; however, now that  you’re all aware that such a repair is possible, I’m  hopeful that you’ll consider passing such hardware along to a friend or  organization that is keen on repairing it. After all, reuse is far  preferable to recycling or landfill…
 

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