Problem with Samsung ps43d490 PDP

[snipersquad100]

Re: Problem with Samsung ps43d490 PDP

Vs and va are both 0v, that's in normal mode without the jumper and lvds connected.

[tom66]

Re: Problem with Samsung ps43d490 PDP

Your problem looks like X- or Y-main short. Unplug both X- and Y-main and check the Vs, Va. Only need to check those two.

[snipersquad100]

Re: Problem with Samsung ps43d490 PDP

Not sure what to expect but voltages are as follows:-
Va = 0.3
Vs = 10.2
B5v = 5.2
Vs con = 0
Ps on = 0.17
Vs on = 0
A5v = 5.2
B15 = 14.6
I get the same readings in test mode with the pin connecter on pin 3 + 4 with ldvs cable disconnected as I do in normal mode.

[snipersquad100]

Re: Problem with Samsung ps43d490 PDP

sorry I wanted to chat with you personally

[tom66]

Re: Problem with Samsung ps43d490 PDP

It runs between the main board and control board.
Why have you posted in two forums? Hard to keep track of both.

[snipersquad100]

Re: Problem with Samsung ps43d490 PDP

Hi tom witch is the ldvs cable?
thanks

[tom66]

Re: Problem with Samsung ps43d490 PDP

1 Y-main + Y-buffer
2 PSU / Power board
3 X-main
4 Main board/video board
5 Control/logic board

[snipersquad100]

Re: Problem with Samsung ps43d490 PDP

Hi tom, the tv wont power up at all, when I press the on button on the front an led blinks, I think its just saying ive touched the touch sensitive button. nothing else happens. Please could you lable the circles on the pic for me just to make sure im working on the right board.
1:
2:
3:
4:
5:
thank you

[snipersquad100]

Re: Problem with Samsung ps43d490 PDP

thanks tom

[tom66]

Re: Problem with Samsung ps43d490 PDP

Several people on eBay have them, I'm a fan of parts4me uk they are cheap but untested with good returns policy. Yes update firmware after installing them.

[snipersquad100]

Re: Problem with Samsung ps43d490 PDP

where is the best place to get these Tom, and do I update the firmware after.

[tom66]

Re: Problem with Samsung ps43d490 PDP

X-main plus Y-main need replacement.

[snipersquad100]

Re: Problem with Samsung ps43d490 PDP

Hi, my Samsung has gone pop and is now dead, does that mean the y sustain board has gone.

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

Ok, new 1.6 X-main came in today. I've had a play with the voltages and I settled on some. I don't know if voltages have a 'sweet spot' but it certainly seems so!

Took me ages to try and get rid of the pink spots, raised Vscan to 195v with no effect. For a while the only thing that seemed to get rid of it would be to raise the VS to around 212v and I really didn't want to do that. So in frustration I set the voltages with the set on and bingo! I found a good compromise between image quality and voltages (image is almost perfect to me)

The panel settings are as follows...

VA = 58v
VS = 207v
Vscan = 185v

I managed to dial them in too...

VA = 59v
VS = 208v
Vscan = 187(8)v DMM kept jumping between the two

I think these are as near as I'm going to get, I guess these are not too far out as to cause premature failure Tom?

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

Cheers for the advice Tom, I've got a good set of VDE screwdrivers and some insulated gloves which I've been using but I will certainly feel safer doing the way I've been doing (and the way you advised)

I'm probably going on, but thanks for your help Tom, hopefully the new X-main will hold and everything will be good, if not I wont bother you until the replacement goes bang (PS51F5500)

[tom66]

Re: Problem with Samsung ps43d490 PDP

Oh stupid question! When playing with the Vs I have been making adjustments with the TV off then checking the result.

Can I change the pots while the tv is on?

Yes, but be careful. While it is on, high voltage is exposed, and if you slip, you could damage something or electrocute yourself. Maybe best for now to do it only when set is off.

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

Oh stupid question! When playing with the Vs I have been making adjustments with the TV off then checking the result.

Can I change the pots while the tv is on?

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

Yes your right! The guy at Emos said the same thing = they really skimped on the panels which he said it was why they needed the Vs to be 'overdriven' (sorry I dont know the correct term)

I'll have a play with the Vscan when I get the 1.6, as long as overdriving that does not reduce component life like the vs I can live with a few sparklies and I'm sure a low rpm fan will help matters.

[tom66]

Re: Problem with Samsung ps43d490 PDP

Yes playing with Vscan can increase sparklies but it's a matter of finding the best point you can reach. I did like the pic quality on these Samsungs but they really compromised on build quality and have lots of panel issues, shame.

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

Thanks again Tom, I take it that increasing Vscan is not as much a strain on components then. And would it cause (I don't know the term) 'sparkly pixels'

Cheers for staying on and answering my 'noob' questions, I've learnt a lot in the past few weeks!