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_ASH_
Joined: 09 Dec 2011 Posts: 8
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Posted: Fri Dec 09, 2011 7:49 pm Post subject: viewsonic 32in lcd tv power supply ( |
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Hi Guy's please go steady with me as I am no electronics expert,
I have a viewsonic 32in lcd tv power supply (Model: N3260w) that has a power board problem.
I have replaced capacitors CS25, CS24, CS19, CS22, CS21, CS20 & CS 28 (none of them had blown but were bulging, so I thought I would replace them).
However, upon further inspection I have found that on the reverse side of the board, ZD4 & R65 have blown (please see pictures) [img]http://gallery.me.com/alan.harrison#100001/2&bgcolor=blackl[/img]
[img]http://gallery.me.com/alan.harrison#100001/1&bgcolor=blackl[/img]
I am after some advice please on what these are (I assume a Zenner Diod & a resistor), what values and where I can buy these from (I am in the UK).
Many thanks in advance for any help. |
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vtech
Joined: 08 May 2006 Posts: 1264 Location: USA
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_ASH_
Joined: 09 Dec 2011 Posts: 8
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Posted: Sat Dec 10, 2011 9:54 am Post subject: |
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Many Thanks.. _________________ ASH |
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minnie
Joined: 18 Aug 2005 Posts: 2880 Location: Hell
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_ASH_
Joined: 09 Dec 2011 Posts: 8
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Posted: Thu Dec 15, 2011 12:57 am Post subject: |
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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 _________________ ASH |
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_ASH_
Joined: 09 Dec 2011 Posts: 8
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Posted: Mon Dec 19, 2011 2:16 am Post subject: |
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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 |
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jts1957
Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away
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Posted: Mon Dec 19, 2011 3:04 am Post subject: |
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You DID read ALL 24 pages of the thread minnie referenced? All about ZD4; Q7, etc.? _________________ You're over there, I'm over here. |
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vtech
Joined: 08 May 2006 Posts: 1264 Location: USA
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Posted: Mon Dec 19, 2011 3:28 am Post subject: |
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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? |
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train123
Joined: 26 Jan 2010 Posts: 88 Location: Canada
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Posted: Thu Jan 19, 2012 1:12 pm Post subject: |
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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. |
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mostlyHarmless
Joined: 31 Jan 2012 Posts: 1
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Posted: Wed Feb 01, 2012 1:24 am Post subject: Viewsonic TV issues |
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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! |
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