Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

[Vandy30]

Hello Everyone,

Trying to fix an old Plasma for a friend. This is my second thread on here, similar situation (audio, no picture), but last time the issue was on an LED.

TV Specs: Samsung 50" Plasma, Model# HP-S5053

Ymain PN: LJ92-01436A

Symptom: Audio, but no picture, not even the slightest glow, pitch black

Checked so far:

1. Power Supply-Outputting correct voltages on all pins, seems good.
2. Ybuffer boards - upper & lower ICs all look ok visually.
3. Ymain - replaced 2 bad caps, (C5034 & C5000-25V 680 microfarad), but still no picture. Also checked the resistors,fets, & diodes common b/w the upper and lower boards.

Moving Forward:
I believe the issue lies in the Ymain board (PN LJ92-01436A). I'm hearing a clicking noise that seems to be coming from C5907 (B, 472k, 1 kV), which is on a sub assy PCB (PN LJ92-01216B). Should I go ahead and replace that Capacitor or is something else causing the issue?

I've browsed this site and the web for quite some time now, but haven't quite found what I'm looking for and figured I would save some time and ask you guys for some guidance.

I apologize for not posting photos, but I've seemed to misplaced my camera (recently moved). When I find it I will load photos to help troubleshoot.

Thanks,
Vandy30

[Vandy30]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Hello all, checking back in...issue still persists (no picture, but audio) and I believe the problem is on my Ymain board (left side of thumbnail 1). Attached are some photos of the tv back and board in question, I hope the quality isn't too terrible.

I'm still confused as to what is causing the "clicking" noise on the board? Is something trying to power up and is shutting off repeatedly? The clicking noise seems to be coming from an integrated sub assembly board on the Ymain, I took some photos of it as well (thumbnails 3 & 4). In particular I thought it was coming from the blue ceramic capacitor; however, I removed it from the board and it tested good, so I'm not sure what i need to look into next . Any suggestions?

[Hamie]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

There should be a test point marked VSC or VScan.
What it the voltage?

I'm going to hazard a guess and say that the module chips located under the 2 heatsinks are faulty and need to be replaced.


If you don't have a desoldering station it will take some effort removing them as the hearsink will draw all the heat away form an iron.

[Vandy30]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Thanks Hamie,

Vscan = -188.8 VDC

The sticker on the back of the tv indicates Vscan should be -185 VDC...I assume this is within tolerance?

Unfortunately I do not have a desoldering station as this is just a hobby at this point.

How would I go about checking the module chips exactly? Those are new to me.

[Hamie]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

That VScan is ok, slightly high but you can adjust that down with the potentiometer.
Not important just now.

What is the ve voltage, located on the zsus?

[Vandy30]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Does zsus=xmain? I measured this on the board on the right side, facing the back of the tv.

Ve = 112.3 VDC

Sticker states: Ve = 110 VDC

[Vandy30]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

More news:

I was able to find a voltage checksheet online for the TV. Below are the actual vs measured voltages:

Vs(actual)= 200V
Vs(measured)=200V
Vset(actual)=190V
Vset(measured)= 194V
Ve(actual)=110V
Ve(measured)=112V
Vscan(actual)=-190V
Vscan(measured)=-188V
Vsc_h(actual)=-70V
Vsc_h(measured)=~-4V to -7V erratic
Vdd(actual)=5V
Vdd(measured)=5V
Vcc(actual)=15V
Vcc(measured)=15V

Everything looks good except for Vsc_h located on the Ymain. The reading is oscillating from -4 to -7 volts. I've checked most of the neighboring components, but no luck as of yet. Anyone out there know what may be causing a failure at Vsc_h or how to troubleshoot?

[Doc38343]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

More news:

I was able to find a voltage checksheet online for the TV. Below are the actual vs measured voltages:

Vs(actual)= 200V
Vs(measured)=200V
Vset(actual)=190V
Vset(measured)= 194V
Ve(actual)=110V
Ve(measured)=112V
Vscan(actual)=-190V
Vscan(measured)=-188V
Vsc_h(actual)=-70V
Vsc_h(measured)=~-4V to -7V erratic
Vdd(actual)=5V
Vdd(measured)=5V
Vcc(actual)=15V
Vcc(measured)=15V

Everything looks good except for Vsc_h located on the Ymain. The reading is oscillating from -4 to -7 volts. I've checked most of the neighboring components, but no luck as of yet. Anyone out there know what may be causing a failure at Vsc_h or how to troubleshoot?

I'm by no means an expert but I would be checking for a shorted or failed diode like crazy. I usually find one or two after replacing vented caps. Lift one side of the diodes legs if possible but i have had good success checking them in circuit with my VMM. Be sure to power down and discharge the board first. (just saying for safety's sake). There is also the possibility of a partially failing power transistor. The one on my plasma had 7 legs but was basically a mosfet. only one part of it was failed so like you most of my voltages were ok except one rail. Hope this helps.

[Vandy30]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Thanks Doc,

I went back and found 2 diodes that I'm not sure if they've failed or if the surrounding circuitry is causing a strange reading. D5203 is the one in question (probing in photos 1 & 2, close up of location in 4th photo). It is showing s/c. This is on the lower y buffer. The exact same diode on the upper y buffer is reading the same... 0.001V regardless of the position of the leads (see pics 1 and 2).

I'm not very good at desoldering smd's, so before I attempt to do so, I was hoping someone could lead me to a direct replacement for the diodes in question, F4 6H (close up in photo 4) in case I damage during removal or the diode is in fact bad. There are quite a few of these on the board, and most read around 0.45V everywhere else, this is the main reason why I suspect the 2 in question. Any advice is greatly appreciated! Thanks in advance.

[flocko]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

It is a EC11FS4 ultra fast recovery diode 1A 400v marked F4 xx you will need to check it off the board ? if you have any old faulty boards you will find them used almost every were the 6H is the date code Flocko

[Vandy30]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Thank you for the info Flocko. Sorry for the delayed response, been busy.

I was able to remove the 2 diodes I inquired about (F4 xx) and they tested ok out of circuit. I also removed another diode in a different location and a zener diode and both tested good.

I really don't know what I need to do next. I still think the issue is on the Ymain, in particular some of the components related to the Vsc_h since that reading is jumping around from -4 to -7 volts and is supposed to be -70 from what I understand. I've probed all associated components, but not finding anything wrong. I still hear a clicking sound coming from a small transformer, I'm not sure if this is normal or not, but it makes me wonder if the 2 are related.

Any other ideas? Could all the boards be ok, but something actually be wrong with the plasma and I'm just spinning my wheels? This one has me baffled lol.

[Nick's Tvs]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

I just received the exact same tv in my shop today, and just like you I have sound but no picture. All voltages appear correctly on my DMM, but there is no picture.
My set does have a dead give away however since that diode that you are testing and reading 0 going both ways, that one is black on my board along with the 4 little red zeners below it.
If I were you I would check the transistors that are soldered down to the board. Make sure those are good, mine are all registering a short.
I would also check the voltage going from the Y to the buffers.
I luckily have another similar Y sustain with a lot of similar parts I can scavenge from. I will attempt a repair myself and let you know of the results. If I can get it up and running, we can start comparing output voltages, and component readings.
I already closed the shop down for the day so I won't attack this guy until tomorrow morning.
I will keep you posted however.

One last thing, if you have not tried this already, and I would probably get this confirmed by someone else before doing it, but it is possible you may just have a bad buffer. Have you tried taking one of your buffers out of circuit and powering the tv on? Usually if one of your buffers is bad, it will let the screen prime, but won't show picture. By removing the faulty buffer board, you should be able to see the other half of the screen work properly. Try removing the top one first, powering the set, and then checking the screen for picture. If not plug it back in once you have let the residual electricity evacuate, and then try removing the bottom board and then powering the set on and checking the screen one more time.

That is all I could think off other than your Y-sus. Have you done diode and transistor checks on your X-sus/main?

[Nick's Tvs]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Ok, so unfortunately I was not able to power up the TV, I am missing a voltage regulator to replace before I can power it all up but I am fairly confident that I got every part needing replacement replaced.
Here is what I had that was bad

Q5013 part number TA50N28T voltage regulator was registering a short. It caused the entire row of transistors connected in parallel to show a short as well. All the others were ok after I replaced the one. I replaced it with a TA36N30P because that is all I have on hand. Originally I thought that the spare board I had was the same but its a different version, so the voltage regulator is slightly different, and unfortunately I can't find a data sheet on either of these guys so If anyone has info on this little guy please share. I have it soldered in but I doubt I will fire it up with it in there unless I can get confirmation that they are substitutable. Probably will end up buying a spare off ebay or something.

Any way, I also replaced ZD5018 ZD5019 ZD5021 ZD5022 since they were all shorted out. The traces were completely burnt and black, so I had to do some creative soldering to put these back in.

D5023 and D5024 are supposed to register to be almost shorted since they are in parallel with a 15 ohm resistor.

On the other board I had scavenged from, I noticed that the resistor R5004 was registering a short so check out that guy, its supposed to be 100k ohms.

Now honestly it does seem like one or both of your module chips could be bad and need replacement. I will go ahead and take measurements on it and let you know what I get so you can compare.
Let me know if you have any questions on specific component readings in the mean time.
Will post back later.

[Vandy30]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Wow! Thanks for the detailed response Nick's TV's.

Here goes...All diodes/zener diodes to the left of the 10 parallel transistors... D5002, D5023, D5024 are all good as well as the 4 Zener's (8 total) for both the upper and lower y buffers. I actually wish this was the issue lol.

Now, for the 10 transistors in parallel (TA36N30P), I'm checking those with the power off using my diode check function on my DMM and I'm getting:

Source(+) to Drain(-) = 0.417 V

Source(+) to Gate(-) = 0.947 V

I'm getting these values on the bottom most transistor; however, if I test them all at once (positive lead on source on bottom most transistor and negative lead on drain/gate of upper most transistor) I still get the same values. I'm not finding a short anywhere. I believe them all to still be in good working order so long as I'm testing correctly.

I would also check the voltage going from the Y to the buffers.

If I recall correctly, on connectors CN5009 & CN5010 I was roughly:

Pins 1-3 = 27 V

Pins 4-25 = 13-14 V

except, Pin 7 = 0 V or just stray voltage

These values seem to low to me...but I haven't found anywhere that states the output voltages of the Ysustain board.

Have you tried taking one of your buffers out of circuit and powering the tv on?

I have not as of yet. I wanted to make sure this was ok to do...I've read some contradicting information, some say it's ok, others say it could fry some components. I'm open to try this out and see what happens though so long as we can confirm it's not going to hurt anything. Confirmation anyone?

Have you done diode and transistor checks on your X-sus/main?

I really haven't looked too much into the X-sus as it didn't seem to fit the symptoms. From what I understand, the X-sus should still have a picture, but with vertical lines at failed components?

R5004 tested good at 100 K Ohms.

Looking forward to hearing back from you on what your module chips read. I'm not familiar with these components, but am willing to learn.

Thanks for all the help Nick's TV's!

[Nick's Tvs]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Vandy30,

I did not have time to take measurements on the module chip today, it has been such a chaotic day at the shop I will have to open up for a few hours to finish diagnostics tomorrow. I will be getting back to you with the information either sunday or monday once I get my other stuff taken care of.

I did get the same measurements that you did on the transistors.
As for the voltages going from y to buffers, I am not sure what they are supposed to be but I feel like your pins 1-3 are supposed to be near 60volts, not 27v. Usually I have found that samsung plasma tv's will have a 60 or 65 volt line flowing in there.
As for this model being ok to disconnect the top buffer and or the bottom buffer, I was still not able to find any information about that. So if you are not sure I wouldn't do it. But I did buy a small pack of transistor to replace my blown one which should come in within the next week or so depending on shipping, so I will be able to plug in the board and hopefully help you further on the diagnostic and pinpointing exactly what might be wrong with your board.

-Nick

[Vandy30]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Nick,

Just checking in to see if you've had a chance to get your Ysus board up and running and if those voltages going to the ybuffers are around 60 V. I'm about at my witts end with trying to locate the bad component on my board lol. Almost considering sourcing a replacement board, but want to be certain it is the source of the error.

Thanks,
Vandy30

[Nick's Tvs]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Vandy30
I am sorry I have had a really busy week at the shop. I have not gotten my board fixed yet since I have yet to get the part ordered from china. It is supposed to come in today or tomorrow however according to tracking.
Here is what I found out. Please see pictures for the pin numbers.
More than likely those are not the correct pin numbers but just follow my numbers. Also all of the measurements here are taken in diode mode.

Upper pins 2/3/4/5 pins 9/10/12 and pins 14/16/18/20 are 3 groups of pins that are shorted with one another within their groups.

Lower pins 2/3/4/5/10/11/15/16 and pins 6/7/8/9 are 2 large groups of pins that are shorted with one another within their groups.


Here is what I found out with Red probe top pins black probe bottom pins.

Top Pins 2/3/4/5 and 9/10/12 bottom pins 2/3/4/5/10/11/15/16 read 0.344V

Top pins 14/16/18/20 bottom pins 2/3/4/5/10/11/15/16 read .747v

Top pins 14/16/18/20 bottom pins 6/7/8/9 read .505


Here is what I found out with red probe bottom pins and black probe top pins

bottom pins 2/3/4/5/10/11/15/16 top pins 2/3/4/5 read 0.342v

bottom pins 6/7/8/9 top pins 2/3/4/5 read 0.522

bottom pins 6/7/8/9 top pin 6 read 0.464

bottom pins 6/7/8/9 top pins 14/16/18/20 read 0.500v


This is slightly confusing I know, so if the way I am writing this out doesn't make sense, please tell me and I will try to formulate it differently.

[Vandy30]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Alrighty,

First off, Thank you very much Nick, I owe you one. Here are my readings.

Upper pins 2/3/4/5 pins 9/10/12 and pins 14/16/18/20 are 3 groups of pins that are shorted with one another within their groups.

Lower pins 2/3/4/5/10/11/15/16 and pins 6/7/8/9 are 2 large groups of pins that are shorted with one another within their groups.

On the Upper Pin continuity check, groups 2/3/4/5 & 9/10/12 were connected, but 14/16/18/20 were not, on both modules.

On the Lower Pin continuity check, groups 2/3/4/5/10/11/16/17 & 6/7/8/9 were good. It looks like you may have labelled bottom pin 16 as pin 15 in the picture so I think you mean 16/17 if i'm not mistaken?

Here is what I found out with Red probe top pins black probe bottom pins.
Top Pins 2/3/4/5 and 9/10/12 bottom pins 2/3/4/5/10/11/15/16 read 0.344V

For me:
2/3/4/5 to 2/3/4/5/10/11/16/17 read OL/OL (left module/right module)
9/10/12 to 2/3/4/5/10/11/1617 read 0.333v/0.333v

Top pins 14/16/18/20 bottom pins 2/3/4/5/10/11/15/16 read .747v
Top pins 14/16/18/20 bottom pins 6/7/8/9 read .505

For me:
14/16/18/20 to 2/3/4/5/10/11/16/17 read 0.624v/0.624v
14/16/18/20 to 6/7/8/9 read 0.386v/0.386v

Here is what I found out with red probe bottom pins and black probe top pins
bottom pins 2/3/4/5/10/11/15/16 top pins 2/3/4/5 read 0.342v
bottom pins 6/7/8/9 top pins 2/3/4/5 read 0.522
bottom pins 6/7/8/9 top pin 6 read 0.464
bottom pins 6/7/8/9 top pins 14/16/18/20 read 0.500v

For me:
2/3/4/5/10/11/16/17 to 2/3/4/5 read 0.331v/0.331v
6/7/8/9 to 2/3/4/5 read 0.513v/0.513v
6/7/8/9 to 6 read 0.452v/0.452v
6/7/8/9 to 14/16/18/20 read 0.383v/0.383v

In summary, most of the readings are fairly close, with exception of a couple that look to be quite a bit out of tolerance. Is it safe to assume my modules are bad based on these readings? The fact that pins 14/16/18/20 are not connected is concerning as well. If modules are deemed bad, is the only fix just to replace the entire board? These look like they would be difficult to work on.

[Nick's Tvs]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Hello,

So I got the tv running again with the part that came in the mail. Honestly I am not sure if your module is bad or not, I have never really troubleshooted one of those.
I am not very good with helping others with diagnostics over the internet. How do you think we should proceed from here.

[Vandy30]

Re: Samsung 50" Plasma, Model# HP-S5053, Audio, but no Picture

Nick,

Lol, I know what you mean and I appreciate you taking the time and helping me out with this.

I guess I just need to confirm that the board is in fact bad. I know it's receiving all the correct voltages from the Power Supply, so I just need to confirm whether or not it is trying to send the correct voltages to the upper and lower y buffers while the buffers themselves are disconnected. I think that way it would be safe to assume the board is bad. If it's not too much trouble, could you check the voltages on the buffer connectors, CN5009 & CN5010? This way if there is a discrepancy b/w your good board and mine then I will just try to source another board online. I hate to do it that way and would love to fix on the component level, but I don't know what else I could possibly check, short of desoldering components 1 by 1 lol.

If you don't have time to check these I understand, just let me know either way. Thanks again Nick.

Vandy 30