viewsonic 32in lcd tv power supply broken

fidget · Guest

hi. i have read through and cannot find anyone that has had the same problem. i plug this tv in and the red led light on the front just flash's. tv will not turn on.
have repaced all the blown caps on the psu (fsb228-3f01) caps replaced were cs21 cs22 cs28 cs20 cs27 cs23 cs19 cs24 and cs25.
changing these made no difference to the tv, light still flashing.
anyone know what i should look at changing now? i feel it is a fault on the 5v side but don't know what component to look at as they all look ok.
any help will be great.

train123 · Joined: 26 Jan 2010 Posts: 88 Location: Canada

Your problem is likely Q7 (2N4401) and ZD4 (15 volt zener). Replace both and you should be good to go.

fidget · Guest

many thanks. have ordered the parts. will fit them when they turn up.
will let youknow how it goes. Very Happy

fidget · Guest

got the parts today. fitted them and yes it was very fiddely to fit them. ( eye's not as good as they used to be. lol ) put board back into set. covered ears as i turned it on. (no faith in my worklol waited for a big bang. ) it works sound and picture. brillient. then Ow! i have what looks like water marks in between the two screens. got this set second hand from e.bay and it is the first time i have seen it working.
then on the left side of the screen it looks like tiny blue lines from top to about middle and from bottom to middle but not touching.
so my question this time is, is it a simple job to take the screen out and part the 2 pieces? or are they sealed and i will destroy the screen if i try.
and the blue lines? what could that be down to.
many thanks for all the help others have given in this long thread.

subslug · Joined: 29 Oct 2010 Posts: 1

Sign me up as another with a PS failure on the N2751w ViewSonic. Found the forum with a Google search for this exact problem. This thread is a wealth of knowledge regarding this problem, amazing how many have this failure. Almost sounds like a class action suit waiting to happen.

I assume power surges must help to knock these components out, odd why they even bother with the fuse. Our Samsung plasma had a power issue and turned out to simply be the fuse... Thankfully.

Any way, hopefully the new PS will be here in a few days and this can be one less set that ends up in a landfill somewhere.
Thanks for the great forum.

Corbin5 · Guest

Another owner here of a N2750W with the common problem of turning itself on & off. Read through this thread twice and decided to order a used power supply board(FSP204-2F01) from eBay. Once I received it, I plugged it in and figured it would solve my problem just like everyone else. Nope.
Problem still remains. Not sure what I should be checking at this point.

Anyone here have some suggestions?

Thanks.

Guest · Posted: Sun Nov 07, 2010 5:28 pm Post subject:

train123_not logged on · Guest

Check your power supply for the correct supply voltages. This will help you decide what else is wrong. I'm trying to do this by memory but if you check the connector going from the power supply to the main board, you should find +5 V and +12V. The other connector supplies power to the inverter and you should see +24V there.

joseflor · Joined: 27 Mar 2007 Posts: 2

My brother as a viewsonic N3260W with a power supply ref. GPFSP208-3M01 REV:1 P/N: 3BS0096716GP
I found this one http://ep.yimg.com/ca/I/ramplus-2000_2128_16313871 but the shop said it is not a substitute.
Can anyone help me to find where I can get this power supply to buy.

Attached is the link my brother power supply. Note in the picture, the bridge diode is off. I also put in new electrolytic capacitors. Bigger in physical size.

picture >>>> http://www.divshare.com/download/13155967-c53
[img width=600]http://www.divshare.com/img/13155967-c53.JPG[/img]
http://www.divshare.com/img/13155967-c53.JPG
_________________
José Flor

playedataritoday · Joined: 22 Nov 2010 Posts: 1

I was just given an Viewsonic N3252W to try and repair.

It was working for a while on tuner mode and then got stuck on one of
the inputs and would not allow for it to be changed. It was used like
this for a few weeks and then got stuck running the test pattern where every 5 seconds or so a different color screen would show up and then
sometimes the full color bar test pattern. This is the point it was given to me. To turn it on, we need to use the remote and the only way to turn it off is to pull the plug.

I took the back off and took the following measurements at power supply connectors both when the unit is on and when it is in standby.
CN102
On (Standby)
1 - 12.09 (0)
2 - 12.09 (0)
3 - GND
4 - GND
5 - GND
6 - GND
7 - 5.11 (5.11)
8 - 5.11 (5.11)
9 - 5.11 (5.11)
10 - 3.47 (.062)
11 - 3.57 (.627)
12 - 4.87 (.006)
CN101
On (Standby)
1 - GND
2 - GND
3 - GND
4 - GND
5 - 23.75 (0)
6 - 23.75 (0)
7 - 23.75 (0)
8 - 23.75 (0)
9 - 3.57 (.627)
10 - 4.87 (.006)

I removed the power supply completely and can see no evidence of
faulty capacitors and the voltages all seem to be in range. My only
concerns is CN102 - pin 10, being 3.47V, although I don't have
the schematics so I am not sure what it should be. I might have
expected something closer to 5V.

At one point using the top switches I was able to finally change the input
mode to VGA, and I was able to drive with a netbook and it gives me a
beautiful picture. Although now I am unable to change it to anything else, and the OSD window for "Main:" stays on the screen.

The voltages at P701 (top side switch board) are as follows:
On (Standby)
Orange - 0 (3.77)
Blue - 3.74 (3.77)
Red - 3.74 (3.77)
Green - 3.74 (3.77)
Yellow - 3.74 (3.77)
Black - 0 (0)
Brown - 3.74 (3.77)

Now I have seen a lot of discussion in this thread possibly pointing to Q7/ZD4. Now this might be a simple question but which board is this on, the PS or the logic board? I don't see any reference designators for Q7 or ZD4 on either. Even though this is an N3252W, my power supply does not seem to be the FSP 212-3F01/02 every is mentioning. The Darfon part number of mine is: 4H.B0350.001 / D2 and the label on the other side indicates it might be: BK0103500106 B40 S000547 2200232015P Rev A.

Does anyone have experience with my specific issues and has anyone seen similar symptoms with their set? I have no problem replacing the surface mount components (provided I can ID them on the board) or even as a second step dropping money on the replacement supply, I just want some confidence the problem isn't something else before I invest anything more than my time. Also since my power supply seems to be a different revision if it comes down to it, is the Power-On version with the adapter cable still the right one?

All help is appreciated.

Stephen
[email protected]