viewsonic 32in lcd tv power supply broken

[joefair2]

Hey rtrantham1,
Is Q7 a 2N4403 [PNP] (marked with a "2T") or a 2N4401 [NPN] (marked with a "2X") ???

Mine is damaged and all I can see is the "2".

It looks to me like it's a 2N4403 but I can't tell for sure.

Also, on the other side of the board, just wanted to make sure, is the positive lead of C33 supposed to be facing C7?

Sorry for all the questions
I wish I had a good power supply to look at and answer my own questions.

[gregoryp]

OUR 18 MONTH OLD 3250W QUIT THIS WEEK DUE TO A POWER SUPPLY BOARD FAILURE. I REACHED THE HEAD OFFICE OF VIEWSONIC....NICK AT 800-688-6688 EXT 111 AND HE ADMITTED THE REPLACEMENT PART IS NOT AVAILABLE AND WILL NEVER BE AVAILABLE AS THE COMPANY THAT MAKES THEM IS OUT OF BUSINESS. HE BASICALLY TOLD ME THE TV WAS A THROW AWAY. ANYONE WHO PAID TO ORDER THE NEW PARTS HAS LOST HIS MONEY. DOES ANYONE KNOW A GOOD CLASS ACTION ATTORNEY?

[rtrantham1]

Alright the answer to your first question is it is 2x(2n4401). I ordered surface mount 2n3904 npn to take its place and I will have the parts tomorrow oct 2,2007 to test this P/S. So I will let you know the results asap. The answer to your second question is the + end of c33 will face the (c7) cap. Please feel free to email me at [email protected] so we can work together on a solution. I did call up edwards repair for viewsonic and got a whole mess of schematics but something just doesn't match up . Let me know if you want a copy of them because maybe I am overlooking something you might be able to shed some light on. Please Email me because I dont check this forum that often.

[rtrantham1]

Well I got the parts in and after replacing q7 transistor,c33,and the rest of the swolen caps.That TV WORKS GREAT!!! So if anyone has a N3260w Viewsonic 99% of the time it is the power supply and the above componets. Please email me for any questions at [email protected]

[rtrantham1]

also if this does not fix it you might have 1 more componet bad which is IC2. This is a type of mosfet. The ID on this piece is ea1532a. Well out of the 5 tvs i manage to get 3 running, but the other 2 need this mosfet.

[beamik]

I am having the same exact issue it seems. My set is the 3250w however – I’m not sure how similar/different the two units are. When I turn on the power the power/status light comes on but there is no image, after a second or two there is a high pitch sound emanating from the power supply area. I pulled out the power supply and have it sitting here, but I had to struggle to get the heat sink cover off. It’s a “Darfon” board. I'm not seeing a Q7 or C33... I have three 1000uF 30 volt caps here... that reside next to the large transformer...

any help is appreciated.

Mike

[beamik]

this board has a sticker on the bottom that reads:

B00102800105 D42 S001738
2200202400 Rev.A


on the front it has:

E162032 VOL. 3
GCI 3AV0 ^SZ
94V-0

DARFON
4H.B0280.001 /C2

[boulavard_55]

Does anyone have the specs for QS4 on the 3260 power supply. I also have a resistor that is cooked. It is R65. I would like to know what the specs are on those 2 items for the 3260.

[rtrantham1]

How do you know qs4 is bad

[rtrantham1]

Oh I do not have access to the schematics anymore, but I have found out that you might need to check ZD3 (Zener Diode) for a short . This diode is use for voltage regulation about 14 volts to be exact which is probably the cause of q7 malfunction. This might help also, if you have a power supply or tv that will come on and will not go off except when power is pulled, then check the resistance across c9 cap and it should read approx. 2Mega ohms. If not then chip L6598d013tr is bad.