Goodmans GTV42P3 42" Plasma TV - Power Board Repair

vtech · Joined: 08 May 2006 Posts: 1264 Location: USA

Old B,

If you take a little time to look at the diagram, you will see that by taking Q101 and (surely meant Q102 instead of Q202), he has simply taken out and disabled the "pre-regulator" circuit. That is EXACTLY why he sees the pixelating effect/ Blk/Wht. during a scene change. (remember picture bowing in/out with analog sets when there was a regulator problem?)

Unit will indeed operate and the remaining stage will attempt to compensate---only not at full regulation that is designed for. There is no magic here my friend! Basic ohms law and Voltage regulation 101.

Old Bassid · Guest

Well vtech, I ain,t got the circuit- I tried to download it but gave up(Iam on dialup-2kB/s). any way, last night I started to think about it- I had forgotten that Mad is probably on 110-120v(here is 240v only)- & so it would be possible to use mains input in lieu of regulator- but really why would one bother?- the risk of damage to rest of set- I certainly would'n't- any way an apology to Mad- seems he really IS a Perfessor!.

joe3666 · Joined: 29 Dec 2008 Posts: 2

RobCX3 · Guest

Thanks for the info! I'm currently troubleshooting a similiar chassis on the component level and find your posts very helpful as I'm unable to locate schematics for this model. Old Bassid is the one who needs to quit wasting posters' time with useless opinions. Thanks again, Mad Professor!

alain28 · Joined: 27 Jan 2008 Posts: 32 Location: France

Also many thanks "MAD PROFESSOR" for report.
(+ world community)
I am trying to fix a unit with R102 & R103 with trouble.
(PCB is burnt under, one resistor cutted)
Here in france I have collected with mine 3 examples.
I will report soon.
_________________
AM

France

Dr.Mentalist · Joined: 04 Jun 2009 Posts: 2

@MAD PROFESSOR
Did replacing these dead parts work?
I am working on a GTV42P4 plasma with LG V6 parts. I found a problem with the goodmans psu (3501Q00055A) which is a similar pcb, dead with the EXACT observations in your first post. Two blown resistors and short across the rectifier (exactly the same part numbers) ect. I dont know weather to get a replacement board or replacement parts (both expensive). So If you could tell me if this is a good fix, it would be GREATLY appreciated!
Thanks Very Happy

Mad Professor · Joined: 14 Sep 2008 Posts: 25

Once I replaced all 5 of the parts listed in post #1 the unit now works again.

The only problem is that i still get the multicoloured pixels when theres fast movement to you are in the menu's, I can live with it.
I just don't have the time to hunt for the problem.

Dr.Mentalist · Joined: 04 Jun 2009 Posts: 2

Thanks Mad Professor!
Just took out the parts to test them but it seems that one of the 20N60C3 is giving a low reading but functions. One 11N80C3 is dead short and another does not functin properly. The diode seems fine.
I had a hunt around in the area but can't find any more faults. One strange thing is that by each mosfet, there is a place for a thru hole diode but no component in there? Maybe it is supposed to be like this or the factory forgot to put them in?
I will replace these parts along with the resistors and report back.
Thanks

mickevans · Guest

:cry:

Hello, I have a Goodmans GTVL19W17HDF thats sick. Initally it was an intermitent problem failing to start up the TV , standby light on but dim. I took it to the repair shop but they told me they cannot get a New board thats needed to power up the set.

Can anyone please help the set is almost new but I dont have any Guarantee..

Ideas, drawings, part numbers and where to obtain them would be great.

Many thanks in advance

polarbear · Joined: 08 Aug 2009 Posts: 1