Philips 42PF9630A/37 horizontal lines

[mrosenberg42]

I have two of these plasmas. One only the top of the screen has these horizontal lines and the other plasma both the top and bottom of the screen has the horizontal lines. The lines seem to be red, green, blue and black. I have done alot of research and this seems to be a buffer board failure. My question is what specifically on these buffer boards are failing and can these be repaired to the component level? I would like to repair the boards rather than swapping. I read somewhere that these might be cold solder joint connection issues but we all know that would be just to easy. I believe I can check the buffer chips one by one for shorting but I think if they shorted to ground the plasma wouldn't even startup. If it is a chip failure can they be removed and replaced? Below are the pics of the plasma that shows the worst signs of the issue. Any help would be much appreciated. Thank You.

[mrosenberg42]

Re: Philips 42PF9630A/37 horizontal lines

Someone has got to have some knowledge of these buffer boards. There are a few companies on ebay that are giving a core of $25 to send in your old board after you buy a refurb from them. They are fixing them and reselling. Anyone?

[el3ctroded]

Re: Philips 42PF9630A/37 horizontal lines

I don't have any actual experience with that, but my thoughts are: Sure you could do chip replacement, if you have the proper tools and soldering experience with high density pin counts. That is likely what the company on ebay is doing, either that or they have contact with a manufacturer who refurbs the boards for them...

High-density chips aren't too hard to solder by hand, once you get the hang of it...

[retiredcaps]

Re: Philips 42PF9630A/37 horizontal lines

I'm amazed by the soldering skill required to do this. See this video (about 9 minutes) on Surface Mount Soldering

http://www.youtube.com/user/CuriousI...31/3NN7UGWYmBY

High-density chips aren't too hard to solder by hand, once you get the hang of it...

[Wizard]

Re: Philips 42PF9630A/37 horizontal lines

These are not Y-buffer failure. You have either bad logic board or mainboard.

Cheers, Wizard

[mrosenberg42]

Re: Philips 42PF9630A/37 horizontal lines

Thanks for the comments. All very helpful. That you tube video is very interesting. As I have been in the electronics industry for years I am sure the soldering won't be a problem I'm just not sure that the buffer chips are the problem. Maybe other components on the board. As Wizard said it may be a bad logic board or main board. As I am not doubting the knowledge of someone who knows infinitely more than me and always will, I still think the buffer boards are the problem. I have read numerous forums of people with the same problem that looked exactly like my picture and the fix was the buffer boards. So now for the plan. Like I said. I have two of these tv's same model number. The 1st plasma has the issue across the whole screen and the second plasma just half the screen is plagued. I am going to remove the buffer that is good and install it in the plasma that the whole screen has the issue. If half the screen comes back good then I feel confident the buffers are the source of the problem. In that scenario I am back to square one. What on the buffer boards are failing? Can a buffer chip fail in that manner or is it more likely other components on the buffer board? I am going to try the buffer swap hopefully within the next couple of days. We had our basement flood and it is now priority. Once again thanks for all the help. Long live badcaps.net!!!!

[nuryev]

Re: Philips 42PF9630A/37 horizontal lines

A friend has offered me his Philips 42inch plasma TV after describing a similar 'horizontal lines' problem with display regardless of input source.

Any new suggestions or experiences to share?

[mbates14]

Re: Philips 42PF9630A/37 horizontal lines

I had a 50" Hitachi that done the same thing. replaced buffers, issue gone.

[nuryev]

Re: Philips 42PF9630A/37 horizontal lines

hi

thanks for the response - can you recall what were the boards you replaced, were they LJ92-01203A?? and the supplier? did you repair it yourself

[mrosenberg42]

Re: Philips 42PF9630A/37 horizontal lines

So after way too long I finally ordered an upper buffer board. I put the board in and the picture looked great. So I put on a dvd with the back of the TV off and let it run for an hour burn in. No problems.

So I installed the back cover of the TV and let it run for about 20 min. and the lines on the upper half of the display started to reappear.

I quickly shut off the TV to avoid damaging the upper buffer board that I just put in. Let it rest for about 15min. and turned it back on. No more lines seen.

So do you think the buffer board is being driven to hard causing the lines or is it heat related?

The bottom half of the screen is fine all the time.

Should I compare the voltage being sent to the lower buffer board vs. the upper buffer board voltage or is this maybe a component on the Y sus board being heated up and causing the anomally.

[b700029]

Re: Philips 42PF9630A/37 horizontal lines

Has anybody ever tried replacing the large blue plastic coated capacitors. On my set they are labled as MPP 335K 2F.

[Wizard]

Re: Philips 42PF9630A/37 horizontal lines

these are not the upper buffers, you need to isolate the problem to logic board or the mainboard. Tip: put up menu. is it good or bad? Good, mainboard is bad due to defective IC because menu is input ahead of the bad IC that only processes the video or bad means logic board is a problem. The lines is missing address line that drives the buffers by bus address that addresses horizontal and vertical lines.

Cheers, Wizard

[mrosenberg42]

Re: Philips 42PF9630A/37 horizontal lines

With the old upper buffer board in the horizontal lines are always present. With the new upper buffer board in the lines are now gone but after about 15min of the set warming up with the cover on the lines started to slowly fade in, which is when I turned the set off.

The lines are there regardless of input and are also there with the menu up when the old board is installed (the original upper buffer board).

Wizard,
If the problem is the logic board like you suggest from your hint (because the horizontal lines are present when the menu is up) then why does the new upper buffer board at least temporarily cure the problem?

I am thoroughly confused. I have read several forums where several people have had the same problems with the same philips chasis and it seems the fix was always bad buffer boards. I am wondering now if this was a temporary fix as in my case.

What do you think the problem components on the logic board would be? I will now be taking a closer look at that. Anything to point me in the right direction would be appreciated. Thanks.

[Wizard]

Re: Philips 42PF9630A/37 horizontal lines

Buffer boards decodes the address lines bus and put one line up for each bus cycle and inject how much brightness after one trigger by the X drive to get plasma cell to light up. Y and Z buffers works together on brightness. The X drive get that pixel to light. Y buffers addresses one line at a time, Z strobes other lines at same time, they are driven just enough to have little precharge all the pixels and just a little trigger by the X (columns) get that cell to alight and sustain, amount of brightness depends on how much voltage applied to that cell by both Y and Z circuits.

Y and X are addressed one pixel at a time with two addresses to place where given line is and a pixel is lit by the X address last. One stuck bit on either Y or X adddress repeats across the screen like you see. The bad address is on the Y bus address bus. That can be either generated bad data from mainboard or the logic board.

Buffer board when defective, it will show up in one IC as noisy lines in one band or blank or IC physically blown out. X buffers is integral to panel itself. If X buffer is bad, panel is junk instantly.

This fault repeats across whole panel, cannot be the Y-buffer boards (the long thin vertical boards on left side, not the YSUS board (that one with heatsinks attached to the Y buffer boards).

Ohh, I see you had menu displayed, that means fault lies with the logic board, not the Y buffer or mainboard itself. It can happen rarely with mainboard, do the logic board first.

Cheers, Wizard

[mrosenberg42]

Re: Philips 42PF9630A/37 horizontal lines

Wizard,
Thanks for all the help. One more question. Like I said early on in the post, I have 2 of these TV's exact same model number one has horizontal lines throughout the whole screen as pictured above and the other has horizontal lines only through the upper half of the picture (have not attached a pic of that set).

Is it possible that the logic board would cause the problem on only the upper half of the screen while the remaining lower half of the picture is perfectly good?

Both tv sets have the exact same symptoms with one exception; one tv set the whole picture is bad and the other set only the upper half is bad.

So if I am logically thinking about this then moving the logic board from one set to the other should move which tv shows the lower half of the screen as being good. Thus confirming or ruling out the logic board. Correct?

And if the problem does not move with the logic board swapping the mainboard between the sets would also confirm or rule out the mainboard.

Please let me know if I am logically thinking this through. Thanks again.

[Wizard]

Re: Philips 42PF9630A/37 horizontal lines

post the pic on that tv with panel half with lines.

Cheers, Wizard

[PlainBill]

Re: Philips 42PF9630A/37 horizontal lines

Wizard,
Thanks for all the help. One more question. Like I said early on in the post, I have 2 of these TV's exact same model number one has horizontal lines throughout the whole screen as pictured above and the other has horizontal lines only through the upper half of the picture (have not attached a pic of that set).

Is it possible that the logic board would cause the problem on only the upper half of the screen while the remaining lower half of the picture is perfectly good?

Both tv sets have the exact same symptoms with one exception; one tv set the whole picture is bad and the other set only the upper half is bad.

So if I am logically thinking about this then moving the logic board from one set to the other should move which tv shows the lower half of the screen as being good. Thus confirming or ruling out the logic board. Correct?

And if the problem does not move with the logic board swapping the mainboard between the sets would also confirm or rule out the mainboard.

Please let me know if I am logically thinking this through. Thanks again.

General troubleshooting technique. If a board is transferred between two sets and the problem follows the board, the board is most likely at fault.

PlainBill

[mrosenberg42]

Re: Philips 42PF9630A/37 horizontal lines

Here are pictures from the set where half the screen is good. I have checked the buffer board for shorts with the method described by coppell tv repair and the board has no shorts and seems OK. Although the heat sinks on the buffer chips get quite hot. Could this be connector solder joints not making good contact on the buffer board?

For a test I put the new upper buffer board back in. With the back cover off I let it run for two hours. No problems. After the two hour mark the buffer chips on the new board start to heat up and the upper half of the screen has lines jumping in and out of the picture. I took a hefty fan and cooled down the upper buffer board while it is still running. The lines disappear for 10 or 15 minutes and then start to come back till I cool it back down.

Like I said I don't want to damage the upper buffer but I do want to figure out what is going on. Thanks to all involved for the help.

[Wizard]

Re: Philips 42PF9630A/37 horizontal lines

I still think best to try with different logic board as well.

Cheers, Wizard

[shovenose]

Re: Philips 42PF9630A/37 horizontal lines

If you put a fan on the one that starts doing it with the cover on does it still do it?