LG MU-42PM11 Y-Sus Help!

[NxB]

I got this TV from a job for free. Cracked it open and the Y-Sus fuse was out. Replaced the fuse and it now goes into protect. Power supply is OK the 190/65 voltages are there when I unplug the Y-Sus board. As is the 5v+

Went through the board. I only get 1.5V at the top.

I do get 14V on the lower portion and 5v on the 3 fets. The 700v Mosfets do nothing.

The panel in this is PDP42V6, from searching this isn't good. Don't want to drop $$ on a new board, I'd rather fix it my self. Seems simple enough.

Pic in next post.

[NxB]

Re: LG MU-42PM11 Y-Sus Help!

Here is the pic.

[PlainBill]

Re: LG MU-42PM11 Y-Sus Help!

I got this TV from a job for free. Cracked it open and the Y-Sus fuse was out. Replaced the fuse and it now goes into protect. Power supply is OK the 190/65 voltages are there when I unplug the Y-Sus board. As is the 5v+

Went through the board. I only get 1.5V at the top.

I do get 14V on the lower portion and 5v on the 3 fets. The 700v Mosfets do nothing.

The panel in this is PDP42V6, from searching this isn't good. Don't want to drop $$ on a new board, I'd rather fix it my self. Seems simple enough.

Pic in next post.

As you have probably discovered, finding information on these is tough. The TV is going into protect mode because the power supply is overloaded.

The first step is to locate the shorted component. Use standard troubleshooting techniques for that. I'm curious, could you post a complete picture of the front and of the back?

PlainBill

[NxB]

Re: LG MU-42PM11 Y-Sus Help!

Of the PCB or the whole thing? I smell something burnt under the large heatsink. Should I take it off?

[PlainBill]

Re: LG MU-42PM11 Y-Sus Help!

Of the PCB or the whole thing? I smell something burnt under the large heatsink. Should I take it off?

Duh!!! That was foolish of me, wasn't it? Pictures of the front and back of the Y-sus, if you would.

Certainly, if you can take the heat sink off without breaking anything, do so. You can see what is burnt.

PlainBill

[Wizard]

Re: LG MU-42PM11 Y-Sus Help!

The reason for hybrid failure is cracked solder joints on one of hybrid module within the big black IC that controls the power MOSFETs in that big black IC.

The group of 3 small transformers are DC-DC converters to different voltage. You are not seeing what they are for. If you do that, measurement of at that transistor is meaningless due to PWM confusing your meter. Measure at the output of the DC-DC converters.

Replace whole board or the hybrid IC if you can source one. Also double check the Y-buffer board (long narrow board plugged into Y-drive board) for burn or cratered IC.

This is reason owners of plasmas junked them after quoted them the estimate of over 400-500. The board themselves from LG and others except samsung was so expensive.

Samsung design of this did right thing not to use hybrid IC at all and we saw huge jump in reliablity.

Cheers, Wizard

[NxB]

Re: LG MU-42PM11 Y-Sus Help!

Its almost off and then I will take pics. I don't think paying $100 for the y board is worth it. The hybrid IC is cheaper, right? I did not see anything wrong with the y board as of yet. Will give it a 2nd look.

This was from a store so it was on all the time.

[NxB]

Re: LG MU-42PM11 Y-Sus Help!

Well... It IS the hybrid IC. Its burnt up. I also fucked up passUP (15V). I think it goes to the top so it shouldn't be tooo bad. Y boards are fine.


The solder on the hybrid grounds was pretty much impossible. I got it off somehow though.

I wanted to keep this but if I guess I will have to sell it if I buy the whole board. Might be better than spending $40 on the hybrid and not fixing it 100%. Unless one of you have one for cheaper.

[NxB]

Re: LG MU-42PM11 Y-Sus Help!

Service Manual

http://drop.io/1u3isnu/asset/mu42pm11-pdf

It has a board layout and parts list.

[PlainBill]

Re: LG MU-42PM11 Y-Sus Help!

Well... It IS the hybrid IC. Its burnt up. I also fucked up passUP (15V). I think it goes to the top so it shouldn't be tooo bad. Y boards are fine.


The solder on the hybrid grounds was pretty much impossible. I got it off somehow though.

I wanted to keep this but if I guess I will have to sell it if I buy the whole board. Might be better than spending $40 on the hybrid and not fixing it 100%. Unless one of you have one for cheaper.

Depending on the money you have in it, I wouldn't even fix it. The panel has a resolution of 852 x 480 - really bad. A Y-sus will cost about $85 from Discount TV Parts. I'm not sure what the buffer would cost , but lets guess half that. I'm not sure what the market is where you are, but locally an LG Plasma with 1000 x 768 resolution goes for $350 on Craigslist. Plus, if it were in a store and on all the time, the panel may be bad.

PlainBill

[NxB]

Re: LG MU-42PM11 Y-Sus Help!

Panel is probably good. The other 2 are ticking away still. No burn in either.

I was paid for the install and got the screen for free. At $350 I'd have 250 of profit from the screen alone.

My hilton burn in plasma does 1280x1024 (upres) and its acceptable. I wanted to use this in its place and sell the burned in one for like $100. I was hoping for an easy fix. If the panel was bad I could sell all the boards on ebay too since everything else is good.

[beeton]

Re: LG MU-42PM11 Y-Sus Help!

Hi. Can anyone send a picture of the lg ysus board font and back showing the pin sockets? I hope to install an new "chip" but damaged the underside of the sockets a bit and can't be sure of the interconnectivity of some of the pins. There are some posted but they were taken without flash (thus a slow shutter speed) and are too fuzzy to make out. Thanks



You can send direct to pbarbati@trebnet.com or post to this question.

Thanks again.