Samsung 50" Plasma HPT5044 No Picture

[dsnyder586]

Re: Samsung 50" Plasma HPT5044 No Picture

Just dropped off the Ysus to be repaired and purchased upper and lower used buffers- will let you know how it goes tomorrow when I get them back. I wrecked the buffers I had so I bought a set of BN96-03361A that according to another thread work fine in these sets. (We will also see) These buffers have 5 IC's compared to 4, so hopefully that means a longer life. Should I add some cooling fans to the back of the set? This will be my personal tv, so I want it to last.

[tom66]

Re: Samsung 50" Plasma HPT5044 No Picture

Five ICs compared to four may mean they are incompatible!!!
Are you certain they are correct part number? For 720p or 1080p?

[dsnyder586]

Re: Samsung 50" Plasma HPT5044 No Picture

I referenced this thread and the numbers match up-

https://www.badcaps.net/forum/showth...ht=LJ41-03882A

If no workie, I am out an additional $60- that would bring my cost over $200 still bearable.

[tieny]

Re: Samsung 50" Plasma HPT5044 No Picture

Alright so I just bought the MOSFET from my local store and just replaced it on my Ysus board.

My tests in the exact order I did them:

Ysus + lower buffer only:
-A brief pink flash appeared on the bottom right of the screen for only a second and the screen went off again.
-Turned it off and back on to see if it happens again and it did.
-Turned it off and back on a third time and now nothing happens.

Ysus + upper buffer without top IC:
-The entire top half of the screen turned on with random noise and hald white screen on the right!

Ysus + upper buffer without IC + lower buffer
-The entire top half of the screen flashed on for a "brief" second and back off to no picture.
-Repeated the process, but nothing happens again.

-Went back to just the Ysus + upper buffer without IC and now I get no picture on the screen again.

I'm hoping I only just shorted the buffers and not the Ysus. I mean the test with the lower buffer flashed for a second and after that I get no more results. If the Ysus was damaged after that first test, then wouldn't that mean that the next test I did with the Ysus and upper buffer would not show a picture if the Ysus was damaged from the lower buffer? But it did show a picture and thus the Ysus wasn't damaged.

Hopefully the Ysus is still good from this conclusion.

Now i'm just about to send in my Y buffers to get repaired and in the meantime I'll probably be rechecking everything on the Ysus board again.


*One Question:
Does the Ysus board spilt its tasks to each Y buffer? For example like the entire top half of the Ysus controls the upper buffer and the bottom half controls the lower buffer? Just wondering if the 5 mosfets on the top left heatsink for mainly connect to the upper buffer and the 5 mosfets on the bottom left heatsink are mainly for the lower buffer?

[tieny]

Re: Samsung 50" Plasma HPT5044 No Picture

So i'm just looking on craigslist for some scopes and I found these two.

http://washingtondc.craigslist.org/m...475823624.html
http://washingtondc.craigslist.org/n...473461198.html

Any opinions?

[tom66]

Re: Samsung 50" Plasma HPT5044 No Picture

Both are good. The Tek is a superior instrument, but since the Elenco is much cheaper I'd choose that. It will suit your needs perfectly. Make sure you get it with either a fixed 10X probe or a switchable one. Fixed is preferred for safety (you won't be able to switch it over and blow the input of the scope.) Consider it at bonus if you can get two probes.

[dsnyder586]

Re: Samsung 50" Plasma HPT5044 No Picture

Ok,

Here is the rundown- I bought two buffers listed above in the thread, and dropped them off for testing with the Ysus Main to be repaired. He replaced the first FET, the blown part and a small resistor (or onboard fuse?)on the main. I plugged the buffers and board in- BINGO! the tv is working perfectly. SO the 5 chip buffers DO work.

[tom66]

Re: Samsung 50" Plasma HPT5044 No Picture

I'm very glad they do, but somewhat surprised. I guess it must have been a revision or design change (or perhaps an earlier version.)

[dsnyder586]

Re: Samsung 50" Plasma HPT5044 No Picture

Ya- it was a bit of a longshot but woohoo!

[tom66]

Re: Samsung 50" Plasma HPT5044 No Picture

Enjoy the TV -- will you keep it?

[dsnyder586]

Re: Samsung 50" Plasma HPT5044 No Picture

Ya- this one is for the living room- think I am going to buy some more broken and fix them, hopefully less board swapping and more component replacement next time.

[tom66]

Re: Samsung 50" Plasma HPT5044 No Picture

So, not bad in all, for about $200 for a 50"?

[dsnyder586]

Re: Samsung 50" Plasma HPT5044 No Picture

Actually, $180 all in- I am happy. When I changed the channel to PBSHD the little menu on the top left said 1080i- that doesn't mean my TV is now 1080i, because of the buffer change right? (one can dream)

[tom66]

Re: Samsung 50" Plasma HPT5044 No Picture

The panel is 720p (actually 768p because it's 1365x768), there is no changing that, it is a physical aspect of the panel (lines and columns.) A 1080p buffer would not work with a 720p panel.

1080i will just be deinterlaced and scaled to fit the screen.

[dsnyder586]

Re: Samsung 50" Plasma HPT5044 No Picture

Got it- thanks Tom!

[tieny]

Re: Samsung 50" Plasma HPT5044 No Picture

Great to hear! I might try it also. I haven't made any progress yet, still looking for a scope. What was the PBA number for the boards you used?

[dsnyder586]

Re: Samsung 50" Plasma HPT5044 No Picture

LJ41-03882A + LJ41-03883A

It's above my mantel right now

[tieny]

Re: Samsung 50" Plasma HPT5044 No Picture

Let us know how it works in the long run!

Anyway I looked up the buffer you suggested and it has six ICs on it? Is that the right one you used?

[dsnyder586]

Re: Samsung 50" Plasma HPT5044 No Picture

Correct, six- not five, sorry!

[tieny]

Re: Samsung 50" Plasma HPT5044 No Picture

Just wondering, which components did the repair guy replace on your Y-sus board?

I just checked the mosfet I replaced and it appears to have a short on pins 2-3 again...

Either these mosfets from my local store is just junk or theres something else wrong with the ysus. But luckily I bought 2. I'm guessing this occured when I connected the upper, lower, and ysus up and tested the TV.

Either something is wrong with the lower buffer board thats causing that short on the Ysus or theres something wrong on the Ysus that controls the lower buffer.

Well I'm about to buy this scope, since its the only person that contacted me back. Know anything about it? Its actually a "Conar model 255" the cl ad was just a typo.
http://washingtondc.craigslist.org/m...488042259.html