Vizio SV320vxt popping fuses like it made it up.

[multimeter]

Re: Vizio SV320vxt popping fuses like it made it up.

also beacause you have a backlight,it means your inverters are working,unless the white screen dissapears after a few seconds

[multimeter]

Re: Vizio SV320vxt popping fuses like it made it up.

sorry did you mean the screen turns white,or the power light?

[budm]

Re: Vizio SV320vxt popping fuses like it made it up.

Do you mean the VZIO LOGO stays white instead of Amber? Or the TV screen just has white glow? Can you see the backlights are on?

[selldoor]

Re: Vizio SV320vxt popping fuses like it made it up.

Hi- Now you have got it back on, I think you should test the voltage across the BIG cap as there seemed to be some doubt earlier that it was operating correctly.
Meter on 600V DC and observe the polarity - HIGH voltage so great care. Once the high voltage is established as ok move on to testing the outputs.

- you might want to read this
https://www.badcaps.net/forum/showth...t=19245&page=2

Post 40 has budm's load and voltage tester which you might want to try to see if your output voltages are sound.

[shwsrvcs]

Re: Vizio SV320vxt popping fuses like it made it up.

my bad, the screen isn't white.. it's just the amber light that turns white, the screen stays dark and moreover, its not getting a signal sent to it that I can see (as in not just the backlights aren't powering up, the main board isn't going up either) on those second set of mosfets on the primary side (q601 I believe) one was also not matching up. could it be that one should be replaced?

so far I've replaced, the rectifier and that first mosfet

that q601 on the board was reading as follows in comparison to the others which I take for "normal"

Q802 }{ 2.590 }{ 0.5 }{ 0.5 }
Q601 }{ 4.45 }{ 0.7 }{ 4.45 }
Q603 }{ 2.421 }{ 4.41 }{ 0.5 }

dg

[shwsrvcs]

Re: Vizio SV320vxt popping fuses like it made it up.

and sorry for the hold up on the reply.. I stayed up all night working on this and a toshiba laptop.... and a website.. and when I wrote about the power light coming back on, it was on my last patch of "awake" time left. I am just now getting back on the job and am heading out to pick up a 16" lcd panel for the laptop and a few fuses for this job. (currently running with one I borrowed from the E321VL I have up next to work on.

[shwsrvcs]

Re: Vizio SV320vxt popping fuses like it made it up.

Hi- Now you have got it back on, I think you should test the voltage across the BIG cap as there seemed to be some doubt earlier that it was operating correctly.
Meter on 600V DC and observe the polarity - HIGH voltage so great care. Once the high voltage is established as ok move on to testing the outputs.

- you might want to read this
https://www.badcaps.net/forum/showth...t=19245&page=2

Post 40 has budm's load and voltage tester which you might want to try to see if your output voltages are sound.

I am crafting one today, need a couple of things from hardware store. going there now

dg

[shwsrvcs]

Re: Vizio SV320vxt popping fuses like it made it up.

errr. didn't get that light fixture quite done, but I am gonna try again in the morning.. I did however find the voltages from the multimeter.. and they are with both the power button pressed and also in standby..

.3 for PSON
3.2 for 12v
5 v for svsb

and still no fuses blown since ever.. oh.. I pulled the main caps and checked em with the meter, they both dropped and then chlled at low reading. I decided to try and replace em just in case, but nope... no 68uf 470V at frys. will try marvac in the morning..

[shwsrvcs]

Re: Vizio SV320vxt popping fuses like it made it up.

oh.. fuses on the main board 2 by the power connection both read at .1 and beep on continuity setting

[selldoor]

Re: Vizio SV320vxt popping fuses like it made it up.

I think you should test the voltage across the BIG cap as there seemed to be some doubt earlier that it was operating correctly.
Meter on 600V DC and observe the polarity - HIGH voltage so great care.


Did you do this before you removed it?

[multimeter]

Re: Vizio SV320vxt popping fuses like it made it up.

errr. didn't get that light fixture quite done, but I am gonna try again in the morning.. I did however find the voltages from the multimeter.. and they are with both the power button pressed and also in standby..

.3 for PSON
3.2 for 12v
5 v for svsb

and still no fuses blown since ever.. oh.. I pulled the main caps and checked em with the meter, they both dropped and then chlled at low reading. I decided to try and replace em just in case, but nope... no 68uf 470V at frys. will try marvac in the morning..

.3 for the ps-on dosent look good...or 3.2 for the 12v...,that with power on?,and standy button pressed for on?

[shwsrvcs]

Re: Vizio SV320vxt popping fuses like it made it up.

I think you should test the voltage across the BIG cap as there seemed to be some doubt earlier that it was operating correctly.
Meter on 600V DC and observe the polarity - HIGH voltage so great care.


Did you do this before you removed it?

no I had not because actually after re-reading the posts inline, I realized that your mention that there was mention about it being bad earlier was in fact the first mention of the possibility of the big cap operating incorrectly in the post. Kinda like foreshadowing but in a less foreshadowy way. But it did plant the idea that it could be bad

Moreover, this board's big cap is 2 smaller caps acting as the big cap side by side. I was heading out to fry's to get a couple things and thought it may be nice to get those 2 "just in case" but guess I thought a thought too soon as the specs for them were glued on the board face down by the glue they put in for assembly time

I cut them loose and then read the bottoms 68uf 470dv... which frys's does not carry, not sure about good ole tandy co. they closed before I got there.. I'm going to Marvac as soon as it opens to try and get em.

But with that in mind, for the set of reading in my last post were done by me indoors with controlled conditions and yest with the power/hold button pressed (vizio white light in front on) and off (amber vizio light lit.)

and so to test the caps, as there are two on this board. what can I do to ensure a proper and accurate reading?

Thanks

DG

[selldoor]

Re: Vizio SV320vxt popping fuses like it made it up.

and so to test the caps, as there are two on this board. what can I do to ensure a proper and accurate reading?

If you have them off the board not a lot (unless you had an ESR meter)
You can test for shorts and that's about all.

[shwsrvcs]

Re: Vizio SV320vxt popping fuses like it made it up.

and so to test the caps, as there are two on this board. what can I do to ensure a proper and accurate reading?

If you have them off the board not a lot (unless you had an ESR meter)
You can test for shorts and that's about all.

i'd only taken them off the board to get the right numbers (which were printed right where they were glued to the board. when they were on the board, they were looking okay though and they ohms seemed to be working okay, but i never checked for the voltage and after i got the numbers I put them back on the board since they weren't bad.

SO they are on the board, I can measure them, and I will... I was hoping for a little procedural assistance to measure, as in series, individualy, etc... and in the case if these results come up that they are both within spec, what is the next item? to review.. the models has:

1 would not power - blowing fuses... fixed, no more fuses have blown
2 vizio symbol lights amber and turns to white, but no picture or audio -
this was where the suggestion for the big cap testing was made as it was confused that the white light meant the lcd panel.


This was where I went off to try and build that light bulb piece and then thought, well , I may as well buy the caps in case they are bad just in case.. came back without the switch for the lights and without the caps since they didn't have the right one.

with nieither in hand, i checked the voltage as suggested in the other messages in line and viola, now here I am. About to test the voltage on the caps.

back in a few with the results.

[shwsrvcs]

Re: Vizio SV320vxt popping fuses like it made it up.

okay, the first big cap 160 dc
The second big cap 0 dc

[shwsrvcs]

Re: Vizio SV320vxt popping fuses like it made it up.

okay.. no 68uf 470v caps here, in all of the different component electronics, a the LCD tv's here, all the power boards --- i dunno.. maybe just 10 or 15 total, but seiously.. in all of those, I could not find a single instance of capacitors being of the same ratings.. not a single one. I don't understand that. perhaps ill ponder that tonight for a while. right now i'm heading to MarVac, with any luck they well have that size.

do any others work if they are done in series or in parallel? and if so. is it the voltage to worry about or the microfarad rating or both and if both how do they interact when wiring up in series or in parallel? I think I need to get some schooling going on here.. this is too many questions for a board, and youtube aint helping me with 10 year old trying to show me how to solder by plugging the damn iron into the wall...

DG

[cashkennedy]

Re: Vizio SV320vxt popping fuses like it made it up.

Im pretty sure for the huge dc cap you can replace it with any voltage from 470v - 600v.

I think i read somewhere also that the capacitance wasnt very important so long as it was rather low.

So if you see something in the range of 470v-600v, with 65-70uF capacitance, then you should just use that. You might have to modify the way its attached / mount it sideways to get it to fit.

[ben7]

Re: Vizio SV320vxt popping fuses like it made it up.

Thats odd that the caps are 470 volt, but if you know the voltage that they will run at, you might be able to use 450 volt ones which are more common. I cant think of any caps that go above 450v

-Ben

[ben7]

Re: Vizio SV320vxt popping fuses like it made it up.

okay, the first big cap 160 dc
The second big cap 0 dc

Um, please read those again, they are in parallel, so they should both read the same!

-Ben

[cashkennedy]

Re: Vizio SV320vxt popping fuses like it made it up.

((The DC power on the primary side is relative to how much it is amplified before the bridge rectifier and whether its US 110v, or europe 220v. Modern designs that can handle european input are usually made with 600v caps i believe.)) nevermind im probably wrong on this, the common voltages for these caps must be slightly lower, perhaps the 450v is the common one for europeans 220v capable designs.