Samsung PN51E450A no picture

[cmorton]

I have a Samsung plasma PN51E450A1FXZA that will not turn on. The stand by light is on and will flicker 5 or 6 times when you try turn power on, but no picture will appear. If you wait another 5-10 minutes the chime will sound and the stand by light comes back on.

I've replaced the power board, XY board, and Y buffer. It still does the same thing. Could anything else be causing the problem...any ideas on how I should proceed? I do not have a multi meter.

Thanks,
Chip

[sordids999]

Re: Samsung PN51E450A no picture

Posting photos showing the parts of the back the TV will proberly help you more with fixing your fault

[cmorton]

Re: Samsung PN51E450A no picture

Ok, I inserted a picture of the back of the tv. I can include close ups of particular parts later today if need be.

Thanks,
Chip

[Hamie]

Re: Samsung PN51E450A no picture

Check voltages VS VA located on the power supply.
Vsc (vscan) located on the y-sustain.
Ve located on the x-main.

Should match your panel sticker

[cmorton]

Re: Samsung PN51E450A no picture

Ok, I was able to pick up a multimeter. Here are the results:
vs: 201 on sticker, 201 on reading
va: 58 on sticker, 58 on reading
vsc: -180 on sticker, -186 on reading
ve: 78 on sticker, 80 on reading

A little more info that may or may not be helpful. The unit is just over 2 years old and there were no problems leading up to this. There is no smoke or burning smell. The led light in the back is strong...blinks every second. I've replaced the power board, xy board, and y sustain since those seemed like the most likely culprits, but nothing changed. I've attached a few more photos. If you need any more let me know. Thanks for helping.

-Chip

[Hamie]

Re: Samsung PN51E450A no picture

Well with those voltages the panel must be glowing?
Darken the room and see if it is.

On the control board (small board in the center of the TV.)

Youll find a small black square with 4 pins sticking up.
The should be numbered 1-4, short out 3 and 4 with a bit of wire or crocodile clip etc.

Disconnect the LVDS cable ( the wire that connects this board to the main av board)

If you get test patterns then the mainboard is your problem.

[cmorton]

Re: Samsung PN51E450A no picture

It doesn't appear the control board for this unit has the 4 pins sticking up to run this test. I attached a pic in case I missed something.

Thanks,
Chip

[Hamie]

Re: Samsung PN51E450A no picture

It does it has 4 holes instead. Just connect holes 3 and 4.

[tom66]

Re: Samsung PN51E450A no picture

Is the panel free of cracks? Even a small one on the edge can stop one of these sets from working.

[cmorton]

Re: Samsung PN51E450A no picture

I don't see any cracks anywhere. Also, I'm having trouble locating where the 3 and 4 hole are.

Thanks,
Chip

[Hamie]

Re: Samsung PN51E450A no picture

[cmorton]

Re: Samsung PN51E450A no picture

Ok, I disconnected the lvds cable and put a plain wire through holes 3 and 4 (see picture). When I turned the tv on I did not get the test patterns...just the same as before. Standby light blinks 6 times, goes out, and no picture.

Thanks,
Chip

[tom66]

Re: Samsung PN51E450A no picture

Do you have Vs and Va during this test?

[cmorton]

Re: Samsung PN51E450A no picture

Yes, I do.

Thanks,
Chip

[cmorton]

Re: Samsung PN51E450A no picture

Would it be worth a try to replace the main board or the control board or is this most likely some kind of issue with the panel and I'm stuck with an expensive piece of trash?

Thanks,
Chip

[Hamie]

Re: Samsung PN51E450A no picture

im unsure if your jumper is making a suitable connection for test patterns. those are copper pads id solder it directly.

[cmorton]

Re: Samsung PN51E450A no picture/update

I replaced the mainboard and the tv powered up just fine. Seems to be working properly now!