Phillips 50PF7320/10 50" plasma no picture or sound

[homerclone]

Hi
I have just received this tv from a friend. the problem with it is that when you power it up you can here two clicks from the psb and two green lights plus the green standby light on front of tv stays on but I get no picture or sound.i will post pictures of psb and a link to a video showing symptoms. I have check psb for bulging caps etc and cant see anything wrong from viewing.
Any help?
I found these test point on psb = is the reading im getting
v snd_-18v = -0.01v
+12v = 12.1v
vton = 79.5v
5v2 = 5.2v
5v_sw = 5.2v
8v6 = 0v
psb model number is LJ44-00108B
I have just left the tv on for 10 mins with just the green standby light on and it has now turned red and will now go to red as soon as power connected to tv

video link
http://youtu.be/fmYFbIyjwSg
Any help Please?
Thank you Mark
He had the psb replaced in 2012 and was working ok

[homerclone]

Re: Phillips 50PF7320/10 50" plasma no picture or sound

any help please

[R_J]

Re: Phillips 50PF7320/10 50" plasma no picture or sound

I just repaired a 42PF5321 Philips, it did have one bad cap in the power supply (bulged) and one (bulged cap) on the Vsus board, but the main fault was a shorted fet (There is more wrong with my Ysus) So I replaced the Ysus (had 2) and it also had one buffer board bad, Chchk the VS and VA voltages, I was testing some other buffer boards to see if they were good and the ones that were bad the small heatsink would get quite warm right away indicating a shorted ic. You can check the buffers with a meter ( as I don't have pictures of your buffers) with buffer board removed, On mine I checked with an ohm meter from the white plug (ysus side) to the pins on the plug that goes to the panel, if you get any low readings or shorts the ic on the buffer is bad.
Depending on the type of short you will get no picture at all or maybe a slight speckle.

[homerclone]

Re: Phillips 50PF7320/10 50" plasma no picture or sound

Hi
Thanks for your reply I tried the power supply with just the main board connected so it would power up and disconnected all other boards to the power supply board and the power supply board seems to shut down ie the two green lights first seen in video go off.(no power going out the buffer plugs or sy & sx plugs.
will post some pics I a bit

[homerclone]

Re: Phillips 50PF7320/10 50" plasma no picture or sound

Hi
Thanks for your reply I tried the power supply with just the main board connected so it would power up and disconnected all other boards to the power supply board and the power supply board seems to shut down ie the two green lights first seen in video go off.(no power going out the buffer plugs or sy & sx plugs.
will post some pics I a bit

Pictures hope this helps someone to help me.

[R_J]

Re: Phillips 50PF7320/10 50" plasma no picture or sound

The vs and va voltage may only show up a few seconds after power on then drop off if they are not connected to the Ysus or if there is a short on the Ysus board. How about a picture of the Ysus board,

When I said check the buffer board I ment Scan buffer boards, Check between the pins on the black plug and the white plug pins there should not be any shorts, if there are then that buffer ic is shorted.
I see these scan buffers don't use heatsinks like mine.

[homerclone]

Re: Phillips 50PF7320/10 50" plasma no picture or sound

Hi
I removed the boars and non of them are shorting out. I now removed the power supply (lj44-00108b) and powered it up I then used the jumper (on_mode) and the board shut down after the two relays clicked again.The on board alarm pcd flashed 13 times witch indicates D5VL fault.
so I think its a power board fault can anyone advice any fix of this board
Thanks for any help in advance
Mark

[homerclone]

Re: Phillips 50PF7320/10 50" plasma no picture or sound

well just a quick update. I removed the buffer boards and the y main board cant find any shorts on buffer boards over the pins. The y main has no bulging caps or any shorted fets etc. I then returned to my original plan of replacing the power board. I got a replacement board but am getting the same results :-(. Howver I stumbled apon this pdf file that show how to test this board and fire it up as a stand alone part. (see file attached) with doing this my original board flashes 4 times on the alarm led indicating the 3v line has failed. so I then ran the test again on the replacement board this flashes 13 times indicating a fault on the 5v line.

Please can someone with more experience look at the pdf file and confirm this is a good way to test these boards please?

This file maybe of some help to others as this is for the Samsung power board not the Phillips as fitted in some other sets

[homerclone]

Re: Phillips 50PF7320/10 50" plasma no picture or sound

[Caleb]

Re: Phillips 50PF7320/10 50" plasma no picture or sound

It appears to be a very good trouble shooting guide, it even gives you suspects to test for each failure. Did your replacement board come with a guarantee? If not you should be able to make one good board from the two since they appear to have different failures. It is also helpful to compare the tests from two boards and find the difference's.

[homerclone]

Re: Phillips 50PF7320/10 50" plasma no picture or sound

Thanks for your reply
The new board has been sent back to supplier who said they will test and refund if found to be faulty.
If I do get a credit I will try and obtain a new ps board and will post my findings

[Dellinger316]

Re: Phillips 50PF7320/10 50" plasma no picture or sound

Does a schematic exist for this beast? My Phillips 50PF9630A/37 with LJ44-00108B power supply quit working. I found IC8003 with its case blown off. The fuse next to D8015 was blown F8002?? I have checked all other fuses an "low' ohm resistors and so far so good. I can fix this if only i had the schematic that has the parts with the correct "8000" series components like the PS-424 troubleshooting guide has.