vizio vp50

[heavymachines]

Re: vizio vp50

how did i know you were gonna say that LOL? yes it was 200k ohm range



say if its a 100k pot shouldn't it range from 0.00 to 100k?

could another device suppressing the pot in circuit?

[tom66]

Re: vizio vp50

If there's excessive parallel load, or if the pot is damaged, you could see those readings.

[heavymachines]

Re: vizio vp50

If there's excessive parallel load, or if the pot is damaged, you could see those readings.

i tested the VS pot and it does not go infinite and this is a good working circuit...



VA pot climbs to infinite very slowly it a clue i think.......

[tom66]

Re: vizio vp50

Definitely a place to consider. I'd order a compatible replacement & see if it goes.

[heavymachines]

Re: vizio vp50

tryng to test pots in breadboard can't get readings on either one...?


but safe to assume i am doing it wrong...

[heavymachines]

Re: vizio vp50

okay got it figured...both pots adjust and no infinite reading in breadboard works perfect far as i can tell so double confirmed ...guess i will have to wait till tomorrow to do power test on tl431...

[heavymachines]

Re: vizio vp50

UPDATE::::

ok still low VA still at 14 volts and has different TL431 and measurement at,

TL431 pin 1 and 3 is 26.6 volts at location U531 on pcb

[tom66]

Re: vizio vp50

There might be a problem around the feedback area of the TL431 and potentiometer.
But I don't know...

[heavymachines]

Re: vizio vp50

Bummer ....that don't sound very confident...umm there is got to be a silly reason why there is low va..... you say feedback area... do you happen to have schematic's on this beast? i have had no luck just owner's manual just about useless...not ready to give up on it yet...power boards too expensive...



does the TL431 sound high on voltage? er close to the limit of it's capacity..

[tom66]

Re: vizio vp50

No schematics as far as I am aware. The part # is LJ44-00132A right?

The feedback is the signal sent back to the SMPS controller to regulate the output. For some reason it's coming out low or the controller is interpreting it as low. Normally I'd have a board in front of me to diagnose, pretty hard to do it over the 'net.

[heavymachines]

Re: vizio vp50

No schematics as far as I am aware. The part # is LJ44-00132A right?

The feedback is the signal sent back to the SMPS controller to regulate the output. For some reason it's coming out low or the controller is interpreting it as low. Normally I'd have a board in front of me to diagnose, pretty hard to do it over the 'net.

close.. it's LJ44-00132B
(Samsung PSPF561A01A)
the set full model number is VP50-HDTV20A

well now that i figured out macros on that camera i can get better pictures for you if you need...Thanks for sticking it out with me i understand your frustration not having it in front of you...i will do what i can to ease that pain...take better pic's and try by best to fallow instructions... and do some research on my end which i have been doing ....














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[tom66]

Re: vizio vp50

I'm going to go out on a limb and suggest swapping the Vs and Va pots; see if the problem then moves to Vs. The circuits for both will be similar; the only real difference is one is 200V and the other is 60V, so try and see if there are any obvious differences between the parts: burn marks etc.

[heavymachines]

Re: vizio vp50

just so you know i had both pots out and put in breadboard and both read 0.00 one way and approx 25 ohm other way both were within 1 ohm of each other...but still will do pot swap if you insist...

[Baileybum1234]

Re: vizio vp50

:

close.. it's LJ44-00132B
(Samsung PSPF561A01A)
the set full model number is VP50-HDTV20A

well now that i figured out macros on that camera i can get better pictures for you if you need...Thanks for sticking it out with me i understand your frustration not having it in front of you...i will do what i can to ease that pain...take better pic's and try by best to fallow instructions... and do some research on my end which i have been doing ....

Sometimes you can find another tv with a simular board.












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[vinceroger69]

Re: vizio vp50

this thread says a Sanyo DP50747 (Chassis P50747-00) uses the same power board does the sanyo manual have a psu diagram in?
https://www.badcaps.net/forum/showthread.php?t=11682

[kevinm34232]

Re: vizio vp50

This is weird I just posted this thread:

https://www.badcaps.net/forum/showthread.php?t=25766

[heavymachines]

Re: vizio vp50

:

yeah sometimes you can but sometimes it hard to find what all share same parts, shop jimmy gives clues sometimes but not always...

[heavymachines]

Re: vizio vp50

and led does not blink at all on ps, i suppose i could take that jumper off... i will tinker with it more on next sunrise..and re read voltages etc...i have a feeling there may be more wrong with the set...but will git-r-done.

[heavymachines]

Re: vizio vp50

And thanks for the suggestions gives me lil more leads one of the post i already seen...but as they say anything is better then nothing..

[heavymachines]

Re: vizio vp50

Man i am such an idiot...


va is fine mistaken it for vg duhh,,,, yes tom do yell i deserve it...



anyways latest update i removed upper buffer and now the set turns on only bottom half screen lights up can't see the menu to switch input to hdmi , put the buffer back in and no dice and those pair of resisters tom we looked at earlier started smoking!!!!!


turned the set off i remeasured those resistors and it still shows 5.5 to 5.6 ohms those are some tough resistors...and removed upper once again and bottom half of screen lights up still... so


most likely dumb question but if i buy a upper buffer is there anything in the y-sustin that could take out the replacement upper buffer? should i check the y-sustin for issues?


my guess would be if it lights up y-sustin is ok most likely but i could be thinking like an idiot again ....???