Question on Philips 42" Plasma

[keico]

Picked up this TV and need some advice

I have done some research but am looking for advice on how to fix

I have read that the buffer boards go bad on them.

I have attached some pics

could anyone please take a look and tell me what they think

[keico]

Re: Question on Philips 42" Plasma

Anybody got some suggestions ???????

[PlainBill]

Re: Question on Philips 42" Plasma

It's probably buffers, or it could be the main logic control board. Main logic control boards (LJ92-01270A) are available for as little as $10 with free shipping on eBay; a pair of Y buffers will cost $150 and up.

I have a pair of these sets, they have a nice picture, but the buffers are a very weak point. Given the cost of a pair of buffers, the age of the TV, and the price of a new 42" plasma, I'm not sure I would recommend repairing it.

PlainBill

[keico]

Re: Question on Philips 42" Plasma

It's probably buffers, or it could be the main logic control board. Main logic control boards (LJ92-01270A) are available for as little as $10 with free shipping on eBay; a pair of Y buffers will cost $150 and up.

I have a pair of these sets, they have a nice picture, but the buffers are a very weak point. Given the cost of a pair of buffers, the age of the TV, and the price of a new 42" plasma, I'm not sure I would recommend repairing it.

PlainBill

The tv cost me nothing . I found it as a throw away

[keico]

Re: Question on Philips 42" Plasma

but the buffers are a very weak point. Given the cost of a pair of buffers, the age of the TV, and the price of a new 42" plasma, I'm not sure I would recommend repairing it.

PlainBill

Can I ask what do you mean when you say that "the buffers are a very weak point"

????

[PlainBill]

Re: Question on Philips 42" Plasma

Can I ask what do you mean when you say that "the buffers are a very weak point"

????

There is an extensive discussion of this plasma panel (and it's support cards) on the Coppell TV Repair blog. If you are standing behind the TV on the left hand side of the TV is the Y-Sustain and Y-Buffers. The buffers are the long narrow boards with 6 ICs (and usually heat sinks) on each. These buffers handle voltages ranging from +200 to -200, so be very careful when power is on.

A common failure mode is one of the buffer ICs shorts. Due to a poor design, the surge is transmitted to both the other buffer and the Y-Sustain, damaging them. IF a buffer shorts, the recommended approach is to replace both buffers and the Y-Sustain at a total cost of about $250. Then sell the TV quickly in case a replacement buffer fails.

The pictures would indicate both buffers are compromised, or the main control logic card is defective.

PlainBill

[mockingbird]

Re: Question on Philips 42" Plasma

Bill, how often is it just the $40 hybrid IC which needs replacement and what are the symptoms of its failure?

[PlainBill]

Re: Question on Philips 42" Plasma

Bill, how often is it just the $40 hybrid IC which needs replacement and what are the symptoms of its failure?

Off topic for this thread. That's a little like asking 'How reliable is the Wankel engine in a Honda?'

A wise-ass answer is 'I have never heard of the $40 hybrid failing in a TV with a Samsung panel.'

The usual symptom of a defective hybrid in a TV using an LG panel is a black screen (hybrid in the Y-Sustain), very dark screen with a little light in the lower right corner (Z-Sustain), blown fuses, and in some cases the TV starts to turn on and turns back off. It is a very common failure in TVs that use the LG Electronics 42X3 panel.

PlainBill

[keico]

Re: Question on Philips 42" Plasma

Thank you so much for the advice.

I will probably start with replacing the bufers boards.

I will get back with you later

Thanks again

[keico]

Here is an update

Ok pulled the Y buffer boards and the Y main

Now according to this blog http://blog.coppelltvrepair.com/2010...er-boards.html I have tested both the upper and lower buffer boards.

On both these boards I get a resistance of around 700 ohms. I ran the doide test and found no shorts.

What do you think.

Also the Y main board I found no swollen capacitors or blown fuses, or blown anything.

Also I know that this has been asked before but how do you bench test a LJ92-01200A Y main board.

aside from checking the fuse and any other obvious damage are there any other techniques.

Please let me know what you think

[PlainBill]

Re: Question on Philips 42" Plasma

About all you can do is test it with only the bottom Y buffer. If the bottom half of the picture is good, replace the upper buffer. If it is bad, replace them both.

PlainBill

[keico]

Re: Question on Philips 42" Plasma

Ok ordered the parts for this TV and still waiting.

My question is being that I found this TV I need a pedestal stand for it. After checking the prices for the actual stand I know I can build one for cheap.

Does anyone have DIY Tv pedastal stand that can support this TV.

I am looking to build a stand and then put it on top of a dresser.

I do not want a wall mount.

any suggestions ???

[pecrie]

Re: Question on Philips 42" Plasma

Hi keico ,


From what I see ,it probably is the IPM ( the hybrid) on the Z-board ,which failed.But it could also be the IPM on the Y-sustain.

I had exactly the same issue ,but on a LG 42" ,with the same pdp panel.
The previous owner ,had it examined ,by an authorized tv engineer.But he found the costs way too high.

So ,I bought it ,just to get familiar ,with the plasma tv`s.Only the tv repair man ,removed the hybrid from the Y-sustain board ,and then left the board loose inside the tv.

Luckily ,I opened the tv first ,before I connected it to the mains ,and switched it on.

So ,after I removed the Y - sustain ,I could do some voltage measuring.Ordered a new Y - sustain ,put it in ,but then I got a picture ,just like you have (sort of).

Ordered the buffer boards (or also called - y-drivers).Put that in ,still the same picture.

So ,then only the Z-board was left.But I didn`t want to buy a whole new board.It would make the repair ,much too expensive.
I then checked the hybrid ,that was removed from the Y - sustain ,and I found the replacement for it.

Had to order it ,on ebay ,from someone in the US.

De -soldering the hybrid ,with my 48 watt soldering station ,could not do the job (even at 450 C degrees)

So ,I bought a 100 watt ,iron ,which works perfectly.

In a training manual ,there is an item ,on testing the hybrid for shorts.

measure between (forward direction)

GND (+) >> Sus-out (-)
Sus-out (+) >> Vs (-)

when both test diodes values are over 0.4 >> OK

reverse direction :

measure between :

GND (-) >> Sus-out (+) ---> text is on the soldering side of the boards
Sus-out (-) >> Vs (+)

when all test diodes values are infinite >> OK

here (-) and (+) are referring to the testleads of your multi meter

If your measurements are like above ,the hybrid is good.If one of the measurements ,don`t comply ,the hybrid is bad.

This is the part nr for the replacement hybrid ,that I used :

STK795-821 Replaces STK795-820 (YPPD-J017C, YPPD-J018C YPPD-J018E)

I got them from startboy 1010 (these replacements are made by Sanyo ,as far as I can see)

He`s got the cheapest price (I think - US $24,99) ,and he delivers fast and good quality.
So ,far I changed 2 hybrids ,and both tvs ,are working fine.

But check the pin layout ,before you order them.

HTH


Eric

[rayrod81]

Re: Question on Philips 42" Plasma

These Philips TVs are an entirely different panel than the LG sets and the IPMs on this model are entirely different than the LG IPMs.

The lines are a symptom of worn out buffer ICs or some other component on the buffer. The washed out image looks as though the timings on the Y-main are bad. You will need a training manual for this panel and an oscilloscope to adjust the timings if they are indeed wrong.

You will not find any problems or shorts with a meter on the buffer boards until they have completely failed. By then you will have to replace the Y-main and both buffers.

[PlainBill]

Re: Question on Philips 42" Plasma

Ok ordered the parts for this TV and still waiting.

My question is being that I found this TV I need a pedestal stand for it. After checking the prices for the actual stand I know I can build one for cheap.

Does anyone have DIY Tv pedastal stand that can support this TV.

I am looking to build a stand and then put it on top of a dresser.

I do not want a wall mount.

any suggestions ???

How elegant do you want it? I built a work stand out of one 2 x 4, 4 drive in nylon feet, 4 angle brackets used in home construction, 16 screws and 4 5/16" carriage bolts. Here's a picture of one, the other is the mirror image. Use wood glue where the pieces of wood cross. Dress it up with plywood or fabric.

My Great Grandfather was a carpenter. His specialty was fine cabinetry. He's spinning in his grave right now.

PlainBill

[keico]

Re: Question on Philips 42" Plasma

How elegant do you want it? I built a work stand out of one 2 x 4, 4 drive in nylon feet, 4 angle brackets used in home construction, 16 screws and 4 5/16" carriage bolts. Here's a picture of one, the other is the mirror image. Use wood glue where the pieces of wood cross. Dress it up with plywood or fabric.

My Great Grandfather was a carpenter. His specialty was fine cabinetry. He's spinning in his grave right now.

PlainBill

I really love the design. I had an idea how I wanted to do it, but after seeing the pic you posted gives me a better way to do it.

Thank you so much

[pecrie]

Re: Question on Philips 42" Plasma

@rayrod81 ,

Yes you`re right.I had the impression ,that this Philips ,was using LG electronics.But it is not.
Instead it uses Samsung panel and electronic boards.Sorry for the confusion.

The IPM`s I mentioned ,are for the 42" LG panel ,42X3

[bbjunkie]

Re: Question on Philips 42" Plasma

This has given me a great idea, I picked up a 50" Samsung the other day with a broken screen. There's a 50" Philips on eBay currently with what sounds like a bad y-sus. Perhaps the same panel - time to investigate

[keico]

Thank you all so much

Wanted to take this time to thank everyone for their advice.

Parts came in and the picture is amazing.

Also thanks for the tips on the DIY tv stand

Here are some pics of the finished project

Thank you all again so much. I could not have done it without the help from you all.

[PlainBill]

Re: Question on Philips 42" Plasma

Neat adaptation of my stand design. Add little trim and it will look (almost) professional.

PlainBill