Philips 42" Plasma - Model 42PF7320A

[ajshoe]

Re: Philips 42" Plasma - Model 42PF7320A

tom,
Have a Phillips 50PF9630A with smeared blotchy picture. assumed X sustain was bad - checked x sustain IPMs, checked out good. I see you mentioned something about a cracked resistor on control board - do u have any more info on where this resistor is located ?? Don't believe my x-sustain board is bad. no bad caps, voltages are good, panel comes on with smeared blotchy pic, menu button does nothing visible. do u remember old post heading ??? thanks

[tom66]

Re: Philips 42" Plasma - Model 42PF7320A

It sounds like you got a defective Y-buffer board which has caused damage to your Y-main board.

[Injustice]

Re: Philips 42" Plasma - Model 42PF7320A

Right,
I changed back to Original Y buffers first - No change - Still Flashing Red Screen

Then I changed back to the Original X Board - No Change also - Still Flashing Red Screen

I did notice that there were 2 Green led lights on the "A2 board" don't know it proper name - [ photos attached ]
One was Solid green ( inner ) and the other was blinking (outer, closer to the A2 writing ) in the same sequence as the flashing of the screen.

Also there was a Humming sound coming from the Y Main board area, the hum was in the same sequence as the flashing of the screen. and blinking of the green light.

Does this mean anything ?

[Injustice]

Re: Philips 42" Plasma - Model 42PF7320A

I will replace the original Y buffers tommorrow and check to see if the flashing stops.

Presently I do not have a Digital Voltmeter, but I believe I can buy one.
No oscilloscope available

[tom66]

Re: Philips 42" Plasma - Model 42PF7320A

With the original Y buffers in place, does it still flash?

I think your new X-main is defective though I did go through a similar process with another member on this forum -- three X-main later we determined it was a cracked resistor on the control board, the resistor was responsible for sending an important signal to the X-main causing identical symptoms to X-main fault.

Do you have any access to a digital voltmeter, or an oscilloscope?

[Injustice]

Re: Philips 42" Plasma - Model 42PF7320A

No change after replacing the X main. which was changed 1st.
After changing the Y buffers - the screen turned Bright red and started flashing / blinking, "like a turn signal"

[tom66]

Re: Philips 42" Plasma - Model 42PF7320A

You should just be able to clean those with isoproypl alcohol. So you saw -no- change in picture after replacing the X-main and Y-buffer?

[Injustice]

Re: Philips 42" Plasma - Model 42PF7320A

done

[Injustice]

Re: Philips 42" Plasma - Model 42PF7320A

working on them now

see attached now

[tom66]

Re: Philips 42" Plasma - Model 42PF7320A

Can we see a picture of the corrosion/deterioration?

[Injustice]

Re: Philips 42" Plasma - Model 42PF7320A

Re-posting

Ok, got the parts and did the following :

Changed the X main board - but there was no difference in the display
left the X-main in and then changed both the Y- buffers - this caused the screen to turn totally red and began flashing in 1 second pulses.

I did notice however when changing the X main, that of the 3 ribbons on the right that connects the screen with the board :
The Top one was OK ie. the gold band was in tact - mostly

The Middle one was lacking some gold on the band

The Bottom was in a bad state - about 50% on the gold on the band was missing - interspersed across the band.

It looks that it was consumed - missing parts for proper connectivity to occur.

Please tell me your thoughts ...

[Injustice]

Re: Philips 42" Plasma - Model 42PF7320A

Anyone wish to take a stab at this ...

tom66

[Injustice]

Re: Philips 42" Plasma - Model 42PF7320A

Anyone wish to take a stab at this ...

[Injustice]

Re: Philips 42" Plasma - Model 42PF7320A

Ok, got the parts and did the following :

Changed the X main board - but there was no difference in the display
left the X-main in and then changed both the Y- buffers - this caused the screen to turn totally red and began flashing in 1 second pulses.

I did notice however when changing the X main, that of the 3 ribbons on the right that connects the screen with the board :
The Top one was OK ie. the gold band was in tact - mostly

The Middle one was lacking some gold on the band

The Bottom was in a bad state - about 50% on the gold on the band was missing - interspersed across the band.

It looks that it was consumed - missing parts for proper connectivity to occur.

Please tell me, your thoughts ...

[tom66]

Re: Philips 42" Plasma - Model 42PF7320A

X-main is common vertical, Y-main is scan vertical. It is a little strange, the X-main would be more accurately called a Z-main (LG use Z-sustain) or common driver. It has nothing, at all, to do with the columns.

[Injustice]

Re: Philips 42" Plasma - Model 42PF7320A

X-axis is horizontal and Y-axis is vertical right ?
and I am having issues with both
the ''X" issue is more predominant and visible in my case,
the "Y" lines are there too, just not as visible.

[tom66]

Re: Philips 42" Plasma - Model 42PF7320A

I'm pretty certain the X-main is at fault as well, you would not see the black part of panel with Y-buffer fault.

[Injustice]

Re: Philips 42" Plasma - Model 42PF7320A

I would just replace the upper and lower Y boards. The bottom chip still looks OK.
I have started on these TVs, I still have a bunch of these Y buffer chips on hand.

Ordered both the upper and lower Y-buffer boards and the X-main, just to be safe.

[Injustice]

Re: Philips 42" Plasma - Model 42PF7320A

Who made the plasma panel in this set? Order boards from that. They may be marked as Philips boards, but they are most likely made by Samsung.

Just checked, Made by Samsung.
and that answers my question :P

[tibimakai]

Re: Philips 42" Plasma - Model 42PF7320A

I would just replace the upper and lower Y boards. The bottom chip still looks OK.
I have started on these TVs, I still have a bunch of these Y buffer chips on hand.