samsung hpt5054 plasma no pic with sound

[ducatilover]

So this plasma was given to me. It has no pic but has sound. Ive checked all over the web and found out there was a settlement with samsung and had them replace the power supply. That didnt fix the problem. Been reading that the y board and buffers mighthave gone out.ive downloaded the manual and checked all my voltages and all the ones i could check were ok. Can anyone tell me were else i might need to check? Could i just have a bad display panel? Ill post a pic with the voltages i got for various points.

Id like to fix this if possible and not expensive. Thaks for having this forum. I hope to learn enough to contribute at some point.

[cadiman]

Re: samsung hpt5054 plasma no pic with sound

I have repaired a few of these. Have you had any luck yet?

There are a lot of good cheap used parts for this model on feebay.

Yboard (on your left) and buffers hold up pretty well on this model.

I have had more power supply and mainboard issues than anything else.

[ducatilover]

Re: samsung hpt5054 plasma no pic with sound

Idlike to know how to check the ybuffers. I got voltage everywhere else. I read the service manual but cant find the test pointfor the ybuffers on my tv

[tom66]

Re: samsung hpt5054 plasma no pic with sound

See:
https://www.youtube.com/watch?v=51SZsfH60EY

The y-main and buffers are a fairly common failure on this set.

[ducatilover]

Re: samsung hpt5054 plasma no pic with sound

When the ymain goes out doesit also take out thebuffers too? I have 209v at the ymain fuse but dont know where the test point is beyond that

[tom66]

Re: samsung hpt5054 plasma no pic with sound

Often, yes. Did you see the video I linked to? I actually went through the same buffer board removed from a TV which blew the buffer.

[ducatilover]

Re: samsung hpt5054 plasma no pic with sound

I looked at it after your post. Ill have to try that. Ill keep you posted

[bjorkson]

Re: samsung hpt5054 plasma no pic with sound

So, is the Y-board bad to begin with that's causing the Y-buffer board to blow out the IC chip? If you were to replaced it, would you have to replaced both the Y-board and Y-buffer at the same time?

[awyatt2]

Re: samsung hpt5054 plasma no pic with sound

look closely at the buffers one of the chips usually burns through. the y main has about seven or eight parts that fail. i have bought kits for the ymain and just replaced the buffers," warning will robinson" as the robot said on lost in space. these buffers are hard to find and around 100 bucks a pop. they fail often and vendors know it.

[ducatilover]

Re: samsung hpt5054 plasma no pic with sound

status update: still working on the darn thing. cant get myself to throw it away until i know i CANT fix it.

[capkid]

Re: samsung hpt5054 plasma no pic with sound

Warning: As some may already know, replacing the burned buffer chip on the upper buffer may not be possible. On a recent chip replacement attempt, I found that the PCB under the chip's legs was badly scorched beyond repair.

[ducatilover]

Re: samsung hpt5054 plasma no pic with sound

Did the test for dim lighted screen in a dark room test didnt see a thing. Havent had much time to work on it. Picked up another lcd for free and it works. Got to getback to fixing this one.

[ducatilover]

Re: samsung hpt5054 plasma no pic with sound

Here are some pics i took of the back side with the voltaged Im getting on several spots of each board. I have the correct voltages that are listed on the label but can seem to figure out why I still have no pic. Is there a spot I can check voltage on the y buffers? in the first pic there is a black connector that connects the y main to the top y buffer. Can I check for power off of one of those pins?

[tw2005]

Re: samsung hpt5054 plasma no pic with sound

Have you gone over the ymain at all and checked for any shorted FETs, possibly Q5500

Q5501 ,Q5302,Q5303,Q5304,Q5306 ?

[ducatilover]

Re: samsung hpt5054 plasma no pic with sound

I have not. Need to buy a meter with an audible setting.
When i had the power supply changed under warranty the service tech told my wife that the main board was bad but that he want sure. I've been reading through the board and read that someone fixed theirs by replacing the main logic. What I'm struggling with is why the panel won't prime or glow. Does the panel get its power from the main logic or the y main?

[tw2005]

Re: samsung hpt5054 plasma no pic with sound

Well it's kind of all tied in together. Obviously the PSU generates the various voltages but the xmain,ymain and buffers drive the panel. There also needs to be a panel on(PON) signal for the drive boards to initialise the panel. Pretty sure the logic board is involved for panel on as well.

If someone has suggested the main AV board as bad, i see a number of people have jumpered pins 3-4 on the small logic ctrl board with the LVDS cable disconnected from the MAIN AV board and the logic control board and it should turn the panel on autogen some test patterns.

never tried it myself.

I've never had to force a panel on so I can't talk from experience.

[tw2005]

Re: samsung hpt5054 plasma no pic with sound

Some of TOMs fine work.

https://www.badcaps.net/forum/showpo...61&postcount=2


Oh, if you have not got diode mode, just measure the resistance at those FETs. if they have shorted it'll show 0 ohms across all pins.

[ducatilover]

Re: samsung hpt5054 plasma no pic with sound

Tested the top y buffer according to the buffer test video and found shorts on the first two chips on the y buffer (top). Lower tested fine

[Glitcher]

Re: samsung hpt5054 plasma no pic with sound

Replace the top y buffer board, and test for shorted mosfets on the main y sustain board

[ducatilover]

Re: samsung hpt5054 plasma no pic with sound

With the y buffer being bad can i still test the main logic board to see if the display will light up?