Vizio plasma TV issue HELP!

[froylan_m]

I have a Vizio P50hdm and when I turn it on it shuts down after 2 seconds. During those 2 seconds I hear a fizzing noise coming from the power supply before it shuts off. Using my multimeter, I checked the Vs and Va voltages on the power supply board, and I got less than 3 volts going to the X and Y sustain boards. The standby voltage is fine which is at 5V. The sticker on the TV says that the Vs is 196V, and the Va is 60V. So is it safe to say that the power supply is the problem and should be replaced? I disconnected the X and Y sustain boards one at a time and the TV still shuts down so I know that it probably isn't those boards. What do you think it is? I think it's the power supply. Any help would be greatly appreciated. Thanks

[froylan_m]

Re: Vizio plasma TV issue HELP!



Here is a picture inside the TV.

[tw2005]

Re: Vizio plasma TV issue HELP!

I think these shutdown with the boards disconnected . Did you backprobe Vs and watch it as you powerup? may see vs for a moment. LG panel and boards and that series blows the IPMs on both the Ysus and Zsus so if they're dead and shorting Vs then that may be the noise from the PSU.

I know on the LG it will go to power on for a second or twn then fault back to standby.

probably not economical to repair these now, ipms are not that cheap and all 4 should be done if one has failed from what I've read if you do one you could be back soon after as they're all the same age.

search the panel number, ysus and zsus board numbers, ipm numbers eg yppd-j016 etc and there should be quite a few threads. I think Toshiba and Sony plasma used the LG panels too at the time so there'll be plenty of info spread over various barnds

[froylan_m]

Re: Vizio plasma TV issue HELP!

I did test the Vs while powering it up and it read over 300V then it immedialtly goes down below 3V and starts going down slowly. This is the same case for the Va. I think the power supply is not supplying the right DC voltage to the sustain boards. I also don't see any bulged capacitors on either board. I actually tested the fuses and one of them were bad on the y sustain board.

[tw2005]

Re: Vizio plasma TV issue HELP!

I did test the Vs while powering it up and it read over 300V then it immedialtly goes down below 3V and starts going down slowly. This is the same case for the Va. I think the power supply is not supplying the right DC voltage to the sustain boards. I also don't see any bulged capacitors on either board. I actually tested the fuses and one of them were bad on the y sustain board.

what's your meter set to? Dc voltage, seems strange 300v but blown fuses on the ysus is probably leaning towards bad ipms and the zsus is powered from the ysus from what i recall.

Not saying you can't have bad psu but bad sustains is highly likely

[ammarben]

Re: Vizio plasma TV issue HELP!

test power supply alone and mesure all voltage

[froylan_m]

Re: Vizio plasma TV issue HELP!

My meter is set to DC Voltage. Should I try replacing the fuse first or test it again without anything connected to it including the main video board? The Z sustain is powered from the Y sustain.

[Alastair E]

Re: Vizio plasma TV issue HELP!

Err-----

WHY on Earth have you started Yet Another thread on this same set with same fault?

You HAVENT got back to us on the recommendations I said in the first thread! All you're doing is wasting time for yourself--and everyone else!!

First Thread--

https://www.badcaps.net/forum/showth...436#post561436

[froylan_m]

Re: Vizio plasma TV issue HELP!

Err-----

WHY on Earth have you started Yet Another thread on this same set with same fault?

You HAVENT got back to us on the recommendations I said in the first thread! All you're doing is wasting time for yourself--and everyone else!!

First Thread--

https://www.badcaps.net/forum/showth...436#post561436

I apologize, and this will be the last thread concerning this issue. I just needed additional help and wanted a little bit more advice. I have your recommendation kept in mind regarding this issue. I'm new to this forum and I wont let this happen again. I didn't mean to cause any trouble for you or for anyone else.

[Alastair E]

Re: Vizio plasma TV issue HELP!

Well--I'm just trying to help. IF you need to revive--what you may think is a dead-thread, its better to make a reply to it stating any tests etc you've tried.
--Everything then is in the same place for easy reference to those looking on--who then may have an idea to further the Cause....

In your current case--You say you have 300V Vs dropping to 0 after a time.

LG PSU's when Unloaded DO overshoot (Would doubt to over 300V though, about 250V is the over-volts trip on 'em--Check your meter!)and then auto-protect shut-down.

--IF you need to check Just the PSU, disconnect the SUS boards from the PSU--Leave everything else connected and take a 240V 150W Bulb and connect it from the Vs pin of PSU to chassis or ground connection pin of PSU at the same plug.

Run the set--Lamp should light and the voltage should be within panel label spec...

IF you have blown fuses on Y-SUS and/or X-SUS then there's surely a short on an IPM. Replacing the fuse will not cure it, just waste a good fuse.

You need to check the IPM's for short-circuits. Google search testing L.G. IPM, there's various tests that can be done.

[froylan_m]

Re: Vizio plasma TV issue HELP!

Ok so I disconnected the X sustain board with the Y sustain plugged in and the TV still shut down, but when I turned it on again and it stayed on. I think the first time it didn't turn on because it detected a disconnected board, but it turned on the second time. When it was on I tested the power supply and it was good actually. Then, I reconnected the X sustain board and the TV shut down both times. So I think the problem is the X sustain because it prevented the TV from turning on. What do you think?

[Alastair E]

Re: Vizio plasma TV issue HELP!

So--Have you checked the IPM's for shorts or not....?