Tip & How-To about Televison & Video

To fix a thermally related TV failure do this:

Look for dried out thermal paste on the transistors / i.c.'s especially on the power supply board.
test while the set is on, carefully! using coolant spray (freon) and, a hairdryer to find heat related faults keep turning the set on and, off to replicate the problem as you heat and cool components until you find the offending component. the coolant is non-conductive and, will not harm anything it touches except you. wear safety glasses and, keep your hands out of the way of the spray nozzle.
remove old non-conducting, heat conducting paste if a component gets too hot and, re-apply the paste.(component heat sink cream)
radio shack sells the coolant spray (component cooler) and, the paste.

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cap placement on psm217-404-h-r power board with coresponding values picture would be nice


This power supply board is also used in Viewsonic VX2835W. 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 by scrubbing these IC and transistor 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 make process.

On my VX2835W 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

Jun 25, 2011 | ViewSonic N3250W Television

3 Answers

Viewsonic VX2835wm won't turn on. Did the usual troubleshooting but to no avail. I have two others that work just fine. Any suggestions? Thanks!


There are 2 boards/parts involved with this problem

a) The power supply board:

The main problem are 4 bad/defective capacitors
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

Aug 13, 2010 | ViewSonic VX2835wm Monitor

2 Answers

Mitsubishi WD-62525 bglod fixed, but inputs are broken


look for dried out thermal paste on the transistors / i.c.'s especially on the power supply board.
test while the set is on, carefully! using coolant spray (freon) and, a hairdryer to find heat related faults keep turning the set on and, off to replicate the problem as you heat and cool components until you find the offending component. the coolant is non-conductive and, will not harm anything it touches except you. wear safety glasses and, keep your hands out of the way of the spray nozzle.
remove old non-conducting paste if a component gets too hot and, re-apply the paste.
radio shack sells the coolant spray (component cooler) and, the paste.

Jul 23, 2010 | Mitsubishi WD-62525 62" Rear Projection...

3 Answers

sound but picture goes black after 10 min


is not the ballast. the problem is the control box

Nov 29, 2009 | Polaroid FLM-2632 Television

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