I had two westinghouse 20v5 monitors do this also just over a yr

I used sillybits example and took one unit apart at first then the other and did some analysis. It turns out that the caps manufactured by Capxon are the problem in my case. I looked that the circuit and found some caps were in parallel where one 220ufd unit by Capxon was bulging and the one made by Taicon was not. In fact all Taicon caps didnt bulge and most Capxon did on the board. Since I didnt want to take a chance I replaced them all except the 150 ufd 400 volt unit made by Taicon since that one was glued in fairly well (laying down) and didnt bulge. Typically that one 400 v cap sees only 120 HZ ripple so its not as stressed. The low voltage output caps need low ESR to filter the high frequency switching supply ripple and are more stressed by this. I ordered mine from Digikey instead of Radio Shack because I want fresh stock and wanted a known brand like Nichicon for the repair. Note some caps are probably stressed when one goes bad expecially when in parallel. I also upgraded the caps to a higher voltage if they can fit standing up or lying down if there is space.

Here are the digikey part numbers to replace all electrolytic caps on the monitor ps board
493-1096 220ufd 50volt qty 3(will stand up and clear cover) qty 3
493-1872 1000ufd 35 volt qty 2( need to lay and glue down to clear cover)
493-1970 22 ufd 100 volt qty1 (will stand up and clear cover)
493-1502 2200 ufd 10 volt qty 2(will stand up and clear cover for original 2200 10volt. also use to replace the 1000 ufd 10 volt cap since no room to lay down a 1000 ufd 35 volt in that location and higher capacity works ok in this case.)

565-1471 150ufd 400volt ( this replaces original ac-dc high voltage filter cap with a better known part [united chemi-con] if you feel you need it or find yours bulging) qty 1

Since I had two monitors doing this I ordered enough for both and am happy to say both now work like a charm. Remember to use a bead of RTV or epoxy (non conductive) around the replacement parts to help glue them to the board (even ones that stand up) and to keep the vibration from working the solder joints loose and/or break the caps legs off at the board to cause a later unneeded failure. Also apply some glue or rtv to the small inductor coils next to the caps as you need to remove the original adhesive to replace the cap from both.


a list of bad or questionable caps brands are listed here

http://capsmod.net/forum/viewthread.php?tid=19&extra=page%3D1

Note this cap problem extends to mother boards and the like too.