There are 2 boards/parts involved with this problem
a) The power supply board:
The main problem are 4 bad/defective capacitors and shorted legs due to bleeding of soldering lead (brownish color).
1. 22uf 400v
2. 47uf 50v
3. 1uf 100v
4. 22uf 35v
You can find them near the PWM IC controller (U601). Replaced all these capacitors regardless they look good. I pulled them out off the board and tested them with my Blue ESR and capacitor tester and found 3 were defective.
Next, you need at least 97% Isoprophyl alcohol and toothbrush to clean the soldering paste. Due to overheating on the primary section / HOT section the soldering leads tend to produce brownish paste which is causing the component parts to SHORT. Concentrate at the back of the board, especially at the U102 (16-pin IC) and Q202 transistor by scrubbing them carefully. I used magnifier to make sure the legs are clean and shiny. Clean the rest of the back and some part on top of the board. Let it dry for 2 hours at least. I did 2 times this cleaning to complete the process.
b) The Main Board
The main board has 2 bad capacitors at C124 and C126. I replaced them and cleaned also the board with alcohol.
That's it. Good Luck.
Roan Mac
Computer Tech
Chapel Hill, NC
They may have High ESR, you need cap meter that can measure ESR (Equivalent Series Resistance).
http://s807.photobucket.com/home/budm/allalbums
http://en.wikipedia.org/wiki/Capacitor_plague
http://www.badcaps.net
I have spent hours on these supplies with no luck.
I would recommend replacing it. Contact Viewsonic at viewsonic.com. Make sure it is out of the 3 year warranty.
Basic LCD monitor and TV troubleshooting guide:
http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide
http://www.fixya.com/support/r7406380-tv_training_manuals
Failed TV and Monitors pictures: http://s807.photobucket.com/albums/yy352/budm/
Learn about bad caps: http://en.wikipedia.org/wiki/Capacitor_plague
Parts: www.shopjimmy.com
Parts: http://interliquidparts.com/
Capacitors kit: http://lcdalternatives.auctivacommerce.com/ he can make you a set of caps for you.
Or www.digikey.com just make sure to use caps with low ESR, 105c, high ripple current, long life rating such as PANASONIC FM or FC series.
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