Riddled TV Repair Forum

basicbri2611 · Joined: 18 Apr 2011 Posts: 3 Location: east sussex

hello members'
would some kind person point me in the right direction' on my Sony PFM-42V1N 42" Plasma Television monitor ?

it's funny because it turns on' but there's no screen shown' ie picture.
inside there are 3 fans and none of them are turning.
when i opened the case i noticed that two capacitors had gone, one 47uf 250volts and one 33uf 250volts, so i changed those two electrolytic capacitors, but still no luck.

any ideas please will be welcome on fault finding.

many thanks
basic

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JTS1957 · Joined: 21 Jan 2009 Posts: 2395 Location: Far, Far Away

Nothing funny about it. You've just described the MOST COMMON failure of flat panel TV/Monitors (Dead &/or Screen not lit,/won't stay lit, with or without sound).

http://elektrotanya.com/?q=showresult&megnev=&megnev2=PFM-42V1N&kategoria=&kat2=all

Start by trying to find the two caps in the schematics. Beware, some service manuals only show to a block diagram level. They want tech to replace "board(s)" NOT discrete "part(s)"

basicbri2611 · Joined: 18 Apr 2011 Posts: 3 Location: east sussex

hi
many thanks for your reply' ive already changed two caps' that were suspect' but still got the same problem.
it clicks goes from red to green but just sits there with no sign of life on the screen.
ive looked at all the rest of the caps through a jewlers loop' but they look ok, i fully understand when you say' they want to change panels and not componets bloody manufactures always looking to screw general public.
im just a novice at this' i can solder realy well and repair tracks and replace componets' but a bit of help fault finding would be good' i love electronics and always been around them, and know not to take them to lightly ie i know they can kill, so i always respect the rules when im working on something like this.
this monitor im working on is for our daughters day care centre, she is dissabled and goes to a daycare 3 days a week, but two weeks ago thier tv just died on them and the powers that be say' thier is no more budget to replace it for them because of cuts.
ive had this sitting in our garage for a while, so i thought that i could fix it and then donate it to the day care centre so they can have a tv to watch.
well that was the plan..lol
anyway thanks for taking the time to reply.
rgds bri Very Happy

JTS1957 · Joined: 21 Jan 2009 Posts: 2395 Location: Far, Far Away

I haven't myself taken the time to download the literature in the link I provided in my last post. It wouldn't have done ME any good anyways as only YOU know the circuit/board/location numbers of the capacitors YOU replaced.

Note: I've replaced more "perfect-looking" capacitors than puffed ones over the many years. Either substitution or testing for value & ESR (at least) are best ways to find 'em.

Those capacitors may (or may not) be shown in the literature and therefore provide a clue as to what specific area(s) and what other part(s) you might then want to check.

basicbri2611 · Joined: 18 Apr 2011 Posts: 3 Location: east sussex

hi JTS1957
thanks for your advice' so your saying that caps dont always look blown or out of shape.

would it be adviseable to take them off the panel before i use a meter on them on my meter i have a caps tester.

years ago i was at college and my course was electronics 224 part 1 i did part 1 and passed' but alas next year on part two' the college did not have enough people to run part two, and thats where it was left' i was realy interested in fault finding but it never happend.
so im just doing the best i can to fix things' have been quite lucky so far with caps blown.
in the uk i used to know a old man who was absoloutely fantastic on anything electronic' and we used to talk to him at bootfairs he used to work on radar on subs for the royal navy' and he said they taught him that well' that he did not normaly use any circuit diagrame' he also said there was web sites for engineers that upload thier fixes from the work that they do' and he used to do the same.
sadly i think he had passed because we stopped seeing him i think he was from a eastern block country like russia or poland' but he was very helpfull.
and myself being a computer tech i sorted out him a nice system for free'
because he was a good man.

JTS1957
would there be any sites like that with fixes out there what i could pay to join or are free to join' so that i can fix this for my daughters day care centre.
my wife calls me a sponge always reading looking on the internet for answers to problems' im 54 so at my age i still like to learn but my passion is electronics.

you take care and thanks for taking the time to reply to me and being so kind.

rgds brian Smile

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