[train123]

I've never had the chance to see a set while it is in the "almost ready to fail" mode. It would be worth taking it apart to visually inspect the capacitors on the power supply to see if you can see some bulging tops. As the capacitors degrade, the controller board would get poor power filtering so it's possible that it could cause the symptoms that you are seeing.

[mostlyHarmless]

Hi all;

I've read through several threads here, here and think I might have one of these power supply issues on my fiance's TV.

I think I can manage the swap out (or even repair) of the PS, but before I go down that road (or before I even try to take apart her TV to test the PS), I'd like your opinion on whether the symptoms could be a PS problem.

Symptom 1: Erratic, spontaneous change in video input (e.g., from Video, to HDMI 1) without any input from the remote.

Symptom 2: Menu listing for one of the video inputs changes between video or YPbPr/YCbCr (maybe this is normal, but I don't recall).

Symptom 3: TV shuts down, but green power light stays on.

Again, many thanks for the info posted here -- if I manage to save the TV, I'll be a hero!

[train123]

I see _ASH_ has posted that he was successful with his repair on the main thread dealing with this problem "viewsonic 32in lcd tv power supply broken". I'm glad he was able to use some of the knowledge the members have posted.

[vtech]

Alan,
Without a schematic it is not going to be easy. Did you follow the link that minnie posted ? There is a good bit of discussion there that could be helpful.
Going back to your problem;
While I am not familiar with the specific circuit, based on your description, it sounds like the zener is trying to clamp too much of a voltage on that rail?(perhaps something else is shorted or leaky on that same circuit prior to the zener causing it to overheat and eventually fail?)
The ticking sound is probably related and more likely coming from a coil or a transformer in the same circuit. There seems to be a thread about a surface mount Q7 that also goes out? Did you follow all the parts listed on that kit?
Go back thru the thread and may want to see if you can contact someone like; [email protected]. ---not sure if it's still a good email?

[jts1957]

You DID read ALL 24 pages of the thread minnie referenced? All about ZD4; Q7, etc.?

[_ASH_]

Hi Guy's... Someone please help me.

I have replaced the following:
ZD4, CS21, CS22, R65

Everything worked fine but with a ticking noise (about every second), I then checked the power supply & ZD4 was really hot (to the point it had broke the solder, I now have the problem where if ZD4 is soldered in or desoldered and power it up, the light flashes red, Amber, then green, then straight back to red. but if I keep pressing the standby button (about 10 times) the green light stays on and the tv powers up.

Can someone please give me an idea where to look as I have been therough the board several times and can't see anything wrong.. I would appreciate help ASAP as I need to sell this to make some space.

Many thanks in advance

ASH

[_ASH_]

Hi Guy's... I have replaced the parts and all is working now (thanks for all input), however I do hear a slight ticking noise coming from the power supply (sounds like a relay or something).

I don't want to get my ear to close as I don't want a big electric shock... lol

Has anyone any ideas what this can be??

Many thanks again.

ASH

[minnie]

http://forum.eserviceinfo.com/viewtopic.php?t=29325&highlight=n3260w

There's plenty here.

[_ASH_]

Many Thanks..

[vtech]

Did a search and found this kit in UK that shows some values..may have other problems though and just may be cheaper to buy the entire board?
http://www.chsinteractive.co.uk/pdf_data/KT41.pdf