LG 50PG1000. Bad YSUS? Strange image behaviour

[Jurki]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

Yeap, sure I will remove it before order a new ones. I'm bit afraid from thermal pad under IC. I have at work soldering station with hot air which is ok for removing TQFP packages, also for SO-8 with thermal pad, but I'm not sure if it is OK for those buffer IC's due to thermal pad under.

HV silicone ?? I never heard about it... I will search for it.

[dabyd64]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

Well its not called that way. I said hv because it has to insolate fairly high voltages, 195V if I remember well, and the buffer legs have 0.3mm between them.
Any dust or humidity and bang!
So, any silicone with high isolation capabilities should work, but beware of the cheap ones that peel off after some time!

[Jurki]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

dabyd64, I have an idea for you. I have found whole PCB board here in Slovakia for 55 eur.

http://www.avelmak.sk/index.php?lm=1...&article=53613

I will buy it, but if my PDP display on top part will be wrong I can sell it to you..

[dabyd64]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

Hi, thanks, its a good pric!
But I'm currently watching an Ebay auction, both ysus boards for 70 euro (used).

[tom66]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

If the panel is truly bad, it would kill the new buffer board, so the board shouldn't be used again. But, I've seen a few of these on this forum, and it's nearly always the buffer boards, which seem to be OK after being replaced.

There might be some cause for reducing the Vsc voltage after replacement as this will affect buffer board reliability. Too low however and a poor image will result so adjust with care.

[dabyd64]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

How much lower? lets say..195--->185, 180v?

[tom66]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

LG Vsc is nominally around 140V, drop it until the panel image starts mal-discharging (lines, ghosting, etc.) Then raise it until the problem goes away.
Note -Vy != Vsc but Samsung uses -Vsc to refer to -Vy and Vsch to refer to Vsc...
(it's confusing...)

[Jurki]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

Guys,

my spare TOP Y-driver arrived ! I have switched on TV. I quickly checked voltages Vs (should be 193V), Va (should be 60V).. Vs is 193.3V, Va is 60.1V. So i put signal into TV and spot two problems on display.

Top part of display (about 1/8) is bit different brightness (probably due to my test with bypassed old Y-driver). Maybe it will disappear after some time.. I don't know.

Second (and biggest) problem is that i have 3 vertical lines (one pixel in width) in middle of display. Two seems to be missing red color and one make a blue noise.

Question is.. It is possible to regenerate display somehow, or display is a dead ?

[tom66]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

Vertical lines sound like a bad panel. Did you disconnect and reconnect the VS/VA on the Y-sus/Z-sus while it was still charged? That can damage the panel drivers which can't be economically repaired.

The brighter portion of the screen should fade after a day or so of normal use.

[Jurki]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

I didn't disconnect anything during charged state. I have big respect to high voltages and especially to DC. Every time I've measured voltages before disconnect anything. Between GND - Vs, GND - Va. Also I did long break between switch off and remove anything.

Panel is defective. That's life...

[dabyd64]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

What a *****! Really bad luck !
At least could you return the ysus?

[Jurki]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

Bad luck..

I'm not sure if I can return it.. I will call there on Monday and ask..
If not do you want it???

[dabyd64]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

Mine was EBR50039005 and EBR50039105, not sure if yours is compatible.
Anyway, I found it on ebay 5 days ago, both ysus boards for 75euro (100usd).
Used, came from a tv with bad panel. Asked if it had any warranty and said 14 days, so I bought them.

[dabyd64]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

Damn!
The boards from Ebay where damaged. No image!
With my old lower YSUS board (it was OK) it made image, but the upper ysus is also damaged because it does a big dark band, I guess that one of the buffer ICs is bad.
I don't think the panel is bad because it was working perfect until it went black suddenly.

So, you pay $100, you get !"·$%
Contacting that idiot, I'm really angry because I wil have to pay the return costs to Canada from Spain, and for that price I would have bought both NEW!!





Jurki How are the shipping costs to Spain? I may buy your board if they are not too high

[tw2005]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

Try negotiating but if they're backyard job if they don't refund in full without returns maybe try a paypal dispute. Not as described DOA.

i've been lucky. out of the 3 duds I've had, one I just paid shipping for another to be sent.

the other 2 just gave full refund when I explained it was dead money sending something not sellable back and both i had confirm the boards had been checked for shorts prior to shipping which they had not since both were shorted on arrival. neither were installed, I test first.

[dabyd64]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

After the initial angry status, I calmed down and told the seller.
He was very kindle and told me for a half refund (He understand that only one of the boards was defective).
I told him, again, that both are bad. The lower YSUS board causes black image, and using my lower YSUS which was OK, and his upper YSUS, shows good image on the lower half of the screen, but shows that dark band on the upper, clearly being a bad buffer IC.
I told that I don't care shipping it back and getting a full refund, or keeping them and getting a partial refund, without the shipping costs.

I'm waiting... damn bad luck around these plasma devices


By the way...the ebr50039005 and the ebr50039001 seem the same board...what do you think?
I did only notice that the tracks in one are all in the same side, while the other are distributed between the top and the bottom of the board

39005:


39001:



EDIT:
I saw that the panel connectors are slightly shifted in the 39001...so no way

[Jurki]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

Hi,

My TOP Y-buffer is EBR50039001.

Company which sell me that spare Y-buffer don't allow return. Sh1t. I made some pressure to that company but without success. So as I can read my board EBR50039001 will not help you.
I share your bad luck with plasma.

I can try to sell that TV with 3 vertical lines - maybe it will be ok, for some pub for watching music channel. Or I will remove all boards and sell them separatly on ebay. But it can take long time just for refund at least something...

Do someone know if selling on ebay of spare boards from TV is effective??

[tom66]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

What nonsense. In EU you can get return in 7day for no reason at all. How did you pay? Card - file chargeback. PayPal - open a dispute. They sold you bad board, that is their problem not yours.

[dabyd64]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

I got full refund without any problem.
Now I bought a new ebr50039005...waiting!
Why dont they allow return? Tell that the part no. you ordered was wrong, that it was a mistake and you didn't even tried to connect...

[dabyd64]

Re: LG 50PG1000. Bad YSUS? Strange image behaviour

Finally I bought and put a new YSUS board.
But...the tv had a black vertical line that appeared only when showing blue color!!
But not in white green or red!
I revised all the connections, cleaned the contacts..still the same.
On light blue it was not so noticeable, but in pure white it was completely dark.



I got a bit angry and left the tv in a corner for a week or so.
But today I tried to turn the TV and it was working perfect.
Some green sparkles, after putting and tightening all the screws on the power boards it almost dissapeared (Was it ground noise?).
So, happy ending after all.