Vizio VP42 Plasma fix

[miniman82]

A guy at work gave me his non-functional HDTV. No standby light, wouldn't turn on. Nothing burned up inside, all boards look new. Problem turned out to be a pair of SMD fuses on a large circuit board (the one with the jacks on it). Jumpered across the partially open fuses, set springs to life. I guess those 2 fuses were the ones supplying +5VDC to the standby circuits, so it was never getting the 'wake up' signal. The ones in question will be in the upper right section of the board, next to a connector coming from the power board in the middle. Gotta love being the neighborhood TV repairman.

[ChrisW6ATV]

I would go and check for bad caps in the power supply if you can. There should be a reason the fuses blew.

Good work, though!

[freakaftr8]

You got lucky! Plasma tv issues suck! Especially those lovely *$(&##(@ IPM modules on the Y and Z sustain boards. ROHS compliant solder makes me furious!

[miniman82]

Originally Posted by ChrisW6ATV

I would go and check for bad caps in the power supply if you can. There should be a reason the fuses blew.

Trust me, that was the first thing I did!

Didn't find any, though. All the caps still look new, and the set works as advertised. I think these 2 fuses just kind of went bad- after all they weren't all the way open, just partially, and they still looked new. When I measured them, I got 10k ohms on one, and 8 on the other. If there really were anything wrong, I'd have expected them to blow all of the way out. Ah well, I'm giving it to my folks. They are already making use of the WEGA HDTV another guy gave me about a week before in their studio, this one will go in the den.

[mbates14]

ive rebuilt those stupid hybrid IPMs. they suck. i still have NOT mastered a way to remove those ICs from the board except heating the living hell out of it with a heatgun. then scorch the board in the process of removal. lol.......

anytime someone calls me up that has a plasma, and said they heard a loud shotgun pop sound and picture went off, the first word out of my mouth is F*** i know what im in for.

[fbuchach]

I take a small wirecutter and cut off the pins, then i take a small pliers and a strong soldering iron to remove the pins from the pwb. That works good. Before replacing the IPM you have to change the SMD electrolytics under the IPM, els the IPM will fail a short time after replacing again.

Here is a interesting Link (in german) where a guy has rebuild an IPM:

http://user.cs.tu-berlin.de/~msaal/P...42SD3_YSUS.pdf

Have a nice day.

Frank

[miniman82]

Warning, above link caused massive IE crash!!!!
Oddly, it works the second time...

[fbuchach]

I use firefox and have no problems.

[freakaftr8]

Cutting the pins are a good idea, but with all these LG Y and Z sustain boards the IPM''s are a little different on pin configurations. Ususally I find that the 18v supply side seems the same. I made a template out of 303 stainless and with small holes for the pins to protrude, I use a butane torch and pull on the heat sync. Works like a charm. The first time I did this I made a half assed template and scoarched the board on a 50X3 Toshiba branded 50" LG plasma Y sustain board. Then I swapped the Y sustain IPM module. Set still works fine ass the area of scoarching had no bearing of effect on the circuits (luckfully) I tell ya, they made these LG's with big heat syncs but no fans. So I used some of my supply and zip tied a fan to each of the four IPM's. (2 on the Y and 2 on the Z) The upper modules rare the ER (error return) modules. They seem to generate more heat than the Sustain IPM's. Then I wired all four fans to a wall outlet 12v supply I cracked open and wired to the power supply. That will prolong the modules but high rates of frequency will still eventually take them out. That Vizio, along with Toshiba, Zenith, Fujitsu, Sensi, Maxent and some other off the walls are all Korean made LG sets. The only propriatary's that I am aware of are Samsung, Pioneer, and Panasonic. Probably others, but LG sets seem to be the troublesome units when it comes to heat and nil on ventilation.

When it comes to these newer plasma sets, the best thing you could do to prolong your investment is put fans on them and keep the back dust bunny free and cool. If not, two to three years is all you are going to get outta them.

BTW. Pioneer PDP units are made in Japan. (surprisingly)

[mbates14]

well the the 50X3 i rebuilt, the peoples faces are maldischarging with orange/red pixies on bright spots for some reason, and the YPPD-016 is getting VERY hot on the Y-sustain. VERY quickly, matter of a minute or two. but the YPPD-015 stays sorta warm, but not super hot.

any ideas?

[mbates14]

Originally Posted by freakaftr8

Cutting the pins are a good idea, but with all these LG Y and Z sustain boards the IPM''s are a little different on pin configurations. Ususally I find that the 18v supply side seems the same. I made a template out of 303 stainless and with small holes for the pins to protrude, I use a butane torch and pull on the heat sync. Works like a charm. The first time I did this I made a half assed template and scoarched the board on a 50X3 Toshiba branded 50" LG plasma Y sustain board. Then I swapped the Y sustain IPM module. Set still works fine ass the area of scoarching had no bearing of effect on the circuits (luckfully) I tell ya, they made these LG's with big heat syncs but no fans. So I used some of my supply and zip tied a fan to each of the four IPM's. (2 on the Y and 2 on the Z) The upper modules rare the ER (error return) modules. They seem to generate more heat than the Sustain IPM's. Then I wired all four fans to a wall outlet 12v supply I cracked open and wired to the power supply. That will prolong the modules but high rates of frequency will still eventually take them out. That Vizio, along with Toshiba, Zenith, Fujitsu, Sensi, Maxent and some other off the walls are all Korean made LG sets. The only propriatary's that I am aware of are Samsung, Pioneer, and Panasonic. Probably others, but LG sets seem to be the troublesome units when it comes to heat and nil on ventilation.

When it comes to these newer plasma sets, the best thing you could do to prolong your investment is put fans on them and keep the back dust bunny free and cool. If not, two to three years is all you are going to get outta them.

BTW. Pioneer PDP units are made in Japan. (surprisingly)

BTW how do you figure ER as error return? never heard it referenced to this anywhere. the training manual mentioned ER as being the Erase pulse.

[Findm-Keepm]

Y'all know that LG service literature is out there for......FREE?

http://136.166.4.200/SubPages/Directview_PDP.htm

There's a ton there - I used a website mirroring program to grab it all, and update it occasionally to get the newest stuff.

Cheers,

[fbuchach]

Hi Brian,

Great Site.

Thanks

Frank

[freakaftr8]

An LG tech I worked with a while back called them error return modules. It makes more sense to consider then erase pulse. I dont know what would be considered error return anyway.

But on the maldischarge issue, set the tv in whitewash in the menu. Then do ground zero setup. Probe Va and Vsc off the PS going to the Y sustain. The label on the panel will tell you correct voltages. After those are set, goto the Y sus. Measure Vs and VSC off the tp. Use the above referenced website, (very helpful). Look up your model series to see where those voltages should be. After all that is done, check the modules 18v. There is a test point. If you are seeing anything under 18, like my set is at 16v where 18 should be, the modules will heat up quick. This is primarly caused by leaky lytics on the sus board. sometines the cap in question could be SMD. Got mine to 17.8v or so and called it a day. If you have access to an o scope, use it! Probe the TP for the Y waveform. You will prob notice alot of the maldischarge will dissapear. If you still have it, could be bad buffer boards or they are being overdriven.

[Wizard256]

I have a question: I had a plasma TV that has absolutely no picture, good LVDS activity, all correct voltages, fuses are fine but all the heatsinks on YSUS and ZSUS still cool. Audio working as well, did change the logic board to no effect.

I know I can see a precharge glow on working plasma panel without picture, but this one did not have that glow.

Can you explain that?

Cheers, Wizard