Samsung PN50A510 P3FXZA Plasma Cycling On/Off

[zape]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Replaced IC101 and still clicking.
Any ideas?

[Unspun01]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

C102 and C131 on this board are both same type of capacitor. You should replace both capacitors since both may be susceptible to failure.

If you only replaced C102, you only did half the repair.

I have repaired several A-series mainboards and C102 and C131 were all that was needed. I have not needed IC101.

Try replacing C131 also.

[zape]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

I did not have a replacement cap so I tried to solder a 47uf electrolytic in a parallel to C131 but it did not help.
Still clicking, after ~15 seconds clicking stops (but PS_ON continues to toggle), green red is blinking on the PSU, red led in front is blinking slowly.

I have Y-SUS board disconnected (still repairing it)
could this be the cause of clicking?

[budm]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

1) When you solder the lytics cap to the to the C102, 131, did you observe the polarity? The Tantalum caps C102, 131 White band is Positive NOT negative like the band on the lytics cap.
2) Is it low ESR cap that you use?

[zape]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

yes and yes
I replaced C102 with a tantalum cap, it's the C131 where I used electrolytic.
the thing is I replaced the C102 first, and then replaced the IC next to it.
So I wonder if I could overheat the cap when replacing the IC

[budm]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Also look to see if the board has other NEC-TONKIN caps at other location too.
https://www.badcaps.net/forum/showth...sung+LN52A650A

[zape]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

I wonder if these symptoms could be caused by Power supply board malfunction.
Is there a way to check if the power board is OK? maybe force PS_ON and VS_ON?

[zape]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Here is a video of the clicking: https://photos.app.goo.gl/438gnUHw7oLNtWu57

[zape]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

So I disconnected Mainboard and shorted PS_ON to ground via 220 Ohm resistor
Still the same clicking.. Now I think it is Power supply board.
Any ideas? Could it be sort of protection? I noticed Va voltage is there at normal level, but VS is 0

[rccrasher65]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

So I disconnected Mainboard and shorted PS_ON to ground via 220 Ohm resistor
Still the same clicking.. Now I think it is Power supply board.
Any ideas? Could it be sort of protection? I noticed Va voltage is there at normal level, but VS is 0

Definately power board, shop jimmy has a repair kit for this power supply. get one for VS line repair, they provide more than what you need, replace all parts they give you, should fix your problem!

[zape]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

I also noticed there is a VS_ON on the PSU, could it be just Vs is turned on separately?

here is what I found in some random samsung manual:

3. If the PS_ON signal changes to Low, the Main SMPS supplies power to the Main Board and Logic Board, and Va and Vg power
is supplied to the DC-DC SMPS.
4. If the VS_ON signal from the Logic Board changes from Low to High, the Main SMPS supplies VS power to the X and Y Main
Board through the DC-DC SMPS, and the screen displays a picture on it.

[zape]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

I think I found it, and failed component is not in the Shop Jimmy kit

[rccrasher65]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

I think I found it, and failed component is not in the Shop Jimmy kit

That's great, what component? kit is for basic use, fixes most problems.

[zape]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

7815 in Vg output was dead, ordered a replacement
This thread actually confused me and I was trying to fix the Main board and did not pay attention to the power board.

[zape]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Confirming 7815 fixes it, also replaced CX820 Just in case

[electromech]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Bought a sammy PN50A550 back in 2008. With the help of this Group when
C102 in 2011 failed I found it and replaced it with a 47uf 63v poly? radial cap (hangs off to the side) TV worked fine for 8 years. and it started with the same symptoms again. at the time I said to H___ with this and went out and bought a LCD ROKU that the AVS forums were recommending at the time. set the sammy off to the side and enjoyed my new LCD (LCD picture quality has come a LONG way since I purchased the sammy plasma). The sammy kept whispering at me "Come on boss, fix me!" so I did. Replaced the same 102 cap.
Per earlier posts in this thread will check C131 and look for NEC-TONKIN caps as well.
I'd like to thank the moderators and all you folks for your posts. I'd have given up on back in 2011 if it wasn't for all the help I've gotten here

[jyoo]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Second post here regarding C102. I replaced C102 5 years ago and recently the power cycle with distorted screen and screeching noise started happening again. I thought it was C131 that others said to try so I replaced that and it didn't work. Then I put the old C131 back and replaced C102 again from 5 years ago and it fixed it again.

[electromech]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Same here. I replaced C102 in the audio section with a poly on the side and it
too failed after a few years. replaced it again and figure I have 4-5 more years.
although LCD's have improved so much since I first bought my Sammy plasma I've already bought a TCL 55r617 to replace it before my 2nd repair on the Sammy. I'll probably park it in a less used room.

[AlexVaq]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

I found this forum while looking for fixes for my Samsung PN50A550. Same problem as described by others. TV goes into a clicking mode with no picture or sound. I wanted to share my final fix for this.

As suggested in this forum, I replaced C102 and C131. Both of the original caps ended up checking out OK once I measured them out of circuit. No luck with this fix for me.

As I was observing the set powered up with the back off, I isolated the relays that were clicking to two on the power supply board. By pressing on the board in this general area I manged to get the set to start working again. Most likely a cold solder joint or cracked trace on the PC board. The set worked fine for a couple of months and then it re-occurred.

This time I removed the power board and found two cracked solder joints on the back side right under the relays. I attached pictures to show the location.

It appears that the through holes are actually sized a little big for the pins. I noticed when I touched them up with the soldering iron, that the solder fell into the hole leaving a gap between the pin and the hole. When the board was initially wave soldered, not enough solder was there to fill the hole and over time this caused the joints to crack. Not sure which one or both were the culprits but I touched up both and the TV is now working fine.

Hopefully this will help others with the same problem where the cap replacement did not work.

That was so helpful! I didn't even have to replace C102, just resoldered the connections and the TV fired again. Thank you guys.

[aaronwt6]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Shoulda replaced it. The problem will return shortly. Heating it most likely just made it work temporarily. The same results would have occurred from simply blowing a hair dryer or other heat source at it for a brief period.