Problem with Samsung ps43d490 PDP

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

^^ Yeah, something to do with that there is only a finite amount of voltage available for the pixel rows.

Anyway, a bit of info for other potential owners of this board. I phoned Emos and they were unsure of the compatibility between a 1.6/1.8 REV X-main as well. Some of them had heard about having to upgrade the logic board if you were going to install a higher REV X-main.

Long story short, they sent out a 1.6 X-main that same day. You just can't fault service like that!!! I just installed the new X-main and the TV works like a champ.

The two boards are definitely different so I am sure Tom66 was correct in his findings.

1.8 Rev X-main = the TV works fine, however start up tests lasts a little longer than normal. The TV will turn off/on a couple of times before finally making its mind up that its safe to turn on and produce the big voltages (i think)

1.6 Rev X-main = the TV turns on almost immediately, almost as if it knows it has the correct part fitted so there is no need to do a start up test.

So the two different parts work, but with my limited understanding there are definietly difference with how the set behaves.

Again, big thanks to Tom66 for putting me on the right track, and aslo a big thanks to Emos for great service!

[tom66]

Re: Problem with Samsung ps43d490 PDP

The firmware has just been updated and everything seems OK the screen gets very - very slightly lighter/darker when displaying a menu box or such like but I am certain that's just my mind playing tricks on me (plus I know a little about how a plasma works - its probably the voltage change when certain pixel rows are exited)

This is called line bleed and is common to all plasmas except the Kuro which appeared to have eliminated it (shame they left the business.)

http://www.avsforum.com/t/1083853/do...tal-line-bleed

I don't drink beer (just a personal preference) but thanks for the offer! Enjoy your TV.

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

NOW UPDATE THE FIRMWARE!!!!!
I cannot emphasise this enough. You will be replacing the X-main in short order again if you do not.

Glad to hear it works -- keep an eye on it! Hopefully it was just a caution and the boards are swappable. If so I may end up doing the same myself for future repairs.

Well I will give Emos and the local authorized Samsung repair center a ring tomorrow to double check and see if the board is OK to use. At the moment I am happy that the problem has been tracked down (thanks to you!) A few more days without a TV wont hurt...

You've not been wrong so far Tom so I'm tempted to get the older revision board just to be safe.

The firmware has just been updated and everything seems OK the screen gets very - very slightly lighter/darker when displaying a menu box or such like but I am certain that's just my mind playing tricks on me (plus I know a little about how a plasma works - its probably the voltage change when certain pixel rows are exited)

I really cannot express how much thanks I have for you right now Tom66 if you would like for me to chuck you some beer tokens just ask!

[tom66]

Re: Problem with Samsung ps43d490 PDP

NOW UPDATE THE FIRMWARE!!!!!
I cannot emphasise this enough. You will be replacing the X-main in short order again if you do not.

Glad to hear it works -- keep an eye on it! Hopefully it was just a caution and the boards are swappable. If so I may end up doing the same myself for future repairs.

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

I got really board and I tried it! I really cant tell you how much I was s**ting myself (pardon the language) Anyway this happened....





You were right Tom66! your the man!!

Though your last post has worried my a bit

[tom66]

Re: Problem with Samsung ps43d490 PDP

The advice I got from a Samsung tech indicates a new control board is advisable if the X-main part REV is changed. Could just be good caution or actually a genuine concern.

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

Thanks for getting back to me Tom, your a star. I'm half tempted just to try it and go for broke. the information on the boards are as follows...

Old X-main
model no 42DH X-MAIN
PCB NO LJ41-09478A
PBA NO LJ92-01796A
REV NO R1.6(10/12/01)

The new X-main is below:

model number 42DH X-MAIN
PCB NO LJ41-09478A
PBA NO LJ92-01796A
REV NO R.1.8(11/05/24)

Seems quite close...

[tom66]

Re: Problem with Samsung ps43d490 PDP

I cannot be sure if they are compatible or not. I wouldn't want to try it.

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

Damn, Emos has sent me a Rev 1.8 X-main!

This is the one with a white square resistor instead of the coil arrangement.

I'm guessing this one wont work?

EDIT: just had a look and the LJxx number is the same, but I've had a read through this thread and it looks like they are not compatible ( Damn Emos! )

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

Well, we are getting ahead of ourselves! gonna plug in the X-main tomorrow and its going to work (i hope)

[tom66]

Re: Problem with Samsung ps43d490 PDP

Suppose with a 5 yr warranty it's hard to go wrong.
I think that scaling of SD TV looks bad on all 1080p displays. 720p TVs like this one only make it look a little better because of fewer pixels.

Whatever you do, please don't scrap the TV. List it on gumtree as faulty or on ebay and it will sell quick.

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

Cheers for the heads up, I doubt I will be going up your way though. the only reason I was going to go for the panny is a 5 year guarantee which is included in the price.

Does not seem like there are too many 40ish inch plasmas about atm I would go to 50in but the scaling on terrestrial TV makes all of them look crap in my eyes :P Had an LG pk590 or something before which everyone raved about - standard telly looked awful

[tom66]

Re: Problem with Samsung ps43d490 PDP

I honestly wouldn't recommend a new X60B Panasonic; too many corners cut (poor components -- worse than the Samsung in many ways!) A used X20/X30 series will do you well... or maybe you can get a new in box one cheap from old stock.

If you're ever in Leeds or visiting the area then I'll buy this TV (faulty) off you for a reasonable price.

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

Oh no! Don't know if I wanted to hear that Well if this does not work I'm running close to the limits of my patience. might have to bite the bullet and buy a new TV.

RS has a nice panny TXP42X60B for three hundred

[tom66]

Re: Problem with Samsung ps43d490 PDP

Ugh, I've had dodgy parts from Emos before, they do NOT test their boards even if they say they do...

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

Hi Tom66, thank you for sticking with me!

I just booted up the TV with the Zsus unplugged and the screen still does flash a funny white colour. I cant quite remember if its flashing the same as last time but when turned on the screen has a white flash mostly in the center on a horizontal plane.

It's kind of like when you used to turn an old tube TV off, where the picture turns white and shrinks down to the center if you know what I mean?

I bought the new Z-sus from Emos so I'm confident that its good, i just hope trying that dodgy zsus and ymain from parts4u has not fried anything else.

[tom66]

Re: Problem with Samsung ps43d490 PDP

Yeah that does sound quite possible, I tested my dead X-main and found the same problem -- a few dead (shorted) FETs. Hope your Y-main is good -- do you still get that screen flash?

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

Quick update:

I bought a new X-main/Z-sus today and its coming in the post. Whilst speaking to the company I bought the board from the guy seems to think along the same lines as Tom

He said what usually goes are some of the FET's on the underside of the board, I have run an analogue tester over the FET's most of them are allowing a current though them in all directions.

Two of them have a considerable voltage drop from the outer pins and testing from the middle pin shows infinite resistance.

I probably don't know what im talking about, but does this mean those two FET's are broken? (i've tried multiple combinations of arming them and no change)

Thanks in advance for any help!

[mcfly666]

Re: Problem with Samsung ps43d490 PDP

hi tom,

I had a look at the boards, but could not find some of the test points mentioned.

I think I'll take a stab at buying another set of boards, though to confuse matters further for me when I spoke to a shop about the boards an enginner told me it sounds as if the Z sus is faulty - I dont even know what one of those is!

[tom66]

Re: Problem with Samsung ps43d490 PDP

It is not likely to be a power board issue if Vs/Va are briefly OK. As far as testing the X- and Y-main on the Y-main there is a point marked VSCAN or VSC and on the X-main a point marked VE. For both of these, the red probe goes on the test point and the black probe on the chassis. 200V DC range, Plug the TV in and you'll get a second or two to measure these and compare to the panel sticker.