Samsung PN50A510 P3FXZA Plasma Cycling On/Off

[vinceroger69]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Has anyone seen and fixed this problem on a Samsung LN52A750R1FXZA? I am having the exact same issues. I had already come across a fix for this by changing out the capacitors and did that, but no luck. Read this whole post and absolutely knew this would fix my TV as well. However, after pulling out the main board, it is different than the ones mentioned on here.

I have searched the board over from top to bottom on both sides looking for c102, because I was just going to go ahead and replace it even if I found it in a different location. No luck finding one on my board. I am definitely hoping that someone used this fix for a Model LN52A750R1FXZA.

Thanks,

Bobby

Maybe start a new thread with the problem you are having as other members may of seen this issue before with your LN52A750R1FXZA

[cliff_hootarski]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

May we have pictures of your mainboard, front and back, please.

[bbsimons]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

I actually started a new thread as recommended. New thread has pics of the board. Thanks

https://www.badcaps.net/forum/showth...538#post628538

[electromech]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Actually, my iron has a similar tip. I was worried about to much heat flowing into R107, which was extremely close to C102. I was afraid I might throw the resistance value off by the heat on the body of the resistor. I have a weller iron as my mainstay with a magnostrictive heating element which really runs too hot for this kind of work.
As for the cap I chose to use,I powered up on a bench supply two electrolytics and a
poly? and tested for leakage current. the electrolytics settled down to about 1 mA at 15V, but the poly? dropped down to 1 uA I'm going to button up the set and run with it.
I figured a cap of that value was not that critical. probably filtered the supply rail for the speaker driver chip. Could be wrong. set powered up perfectly.
I "assumed" that C102 was leaking too badly and was pulling down a supply rail.
An interesting note: I found a self tapping course thread screw in place calling for a machine screw, and visa-verse when I pulled off the back cover.

UPDATE:
Same symptoms have reoccurred a few times this winter when the tv is cold.
one reboot and the set comes on (and the cat runs around the house from the ultrasonic noise blaring out of the speakers) and all is fine.

Guess I'll have to go back in and do the power supply caps next. Still have an excellent picture, no bad pixels.

[yz250f_spud]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Had a PN50A550 that started with squealing and power cycling on start up that go worse over time.

Thanks to those who contributed to this thread. When I first opened it up, I had two blown (bulging) capacitors (C5003 and C5008 both 25v 680uF caps) on the Y-sustain board. I replaced those, but it did not fix the issue.

I ordered P16230CT-ND from digikey and replaced C102.
https://www.digikey.com/product-deta...0CT-ND/4146673
Also C102 is labeled, but the number on the board is hidden under IC101.

This youtube video walks you through how you can diagnose C102 with a volt meter. My upper switching power supply was down to 3.1v at times.
https://www.youtube.com/watch?v=Wawf68FPv9A.

Also, when I pulled C5008 off the board to replace it ripped the soldering pad from the board off with it. Just an FYI that you can solder to the pad on the opposite side of the board and it will work just fine (for through hole mounts).

[Treydogg77]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

I would like to confirm replacing Cap 102 on my main board fixed my unit from cycling off and on! Thanks use Guys! Damn I love this forum!

[Dapper Dan]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

SAMSUNG BN94-01658E C102 location number is under IC101 if you are looking for that first, good luck.

The kit from ShopJimmy is a ceramic replacement cap with no polarity which can be installed in either direction.

Shopjimmy offers no support at all!

IC1203 - STA335BWS (SSOP-36) I could only find this on Ebay!
IC101 - (MP2363DN) Digi-key P/N 1589-1366-ND
C102 - 47uF 10V Tantalum Capacitor Digi-key P/N P16230CT-ND

I used an iron to mount C102 after I mounted IC101 due to size, worked nice for me!

Hope this will help someone!

[Daveleone]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Hey all, I have a PN50A510 that has the power cycling issue. Turns on for ~25 seconds then power cycles, repeats. Here's what I've found so far using the information from this thread:

When power is on:
- Both leds on logic board blinking ~1x/sec
- TV stays on and does not power cycle with PS_ON shorted to GND
- Test pattern is good with logic board pin 3&4 jumpered.

In Standby:
Standby = 5.26v
PS_ON = 4.55v
VS_ON = 0v

Powered on:
Standby = 5.07v-5.08v
PS_ON = 0.19v
VS_ON = 3.26v

Sticker shows:
Vscan = -200v
Vs = 205v
Va = 57v
Ve = 06v

Powered on readings (readings are the same at 0m vs 15min powered on with PS_ON jumpered):
Vscan = -202v
Vs = 208v
Va = 57v
Ve = 97v

Am I within tolerances on those values?

I have already replaced tantalum caps C102 & C131, no change. Have on order IC1203, IC101, and IC102.

Anything else I should be looking at?

Thanks!
--Dave

[Daveleone]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

bump?

[blub]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Replacing C102 seems to have fixed my power cycling problem with a LN37A550P3F. Thanks, this forum is a great resource!

[padler]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

New to this site and this thread is just what I needed to fix my problem. So huge propes to everyone that has posted so far. The question I have is I'm up in Calgary Canada and having a very hard time finding the proper cap to fiz the tv. Is there any other Caps that would work to replace the c102.

[kentso]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

I ordered two from DigiKey.ca A reel with two lonesome capacitors arrived with FedEx here in Ontario, near Toronto two days later and within 15 minutes C102 was replaced and the TV was working perfectly again. The charge was $6 for each cap, $8 for shipping.

[lrwebb]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Wow, you must be OLD!

Hey, watch it now; I've replaced many a discrete component in the last thirty years. (Micro-miniature repair for US Navy; vhf,hf radios, radar, mainframe computers, mini's, and desktops), replaced power supply caps in over two hundred out of warranty monitors working IT Support for FEMA (everyone else thought they were unrepairable and needed emergency funds to replace. Old Guys rock !!!

[lrwebb]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Thanks everyone; have the same issues with Samsung PN50A510; ordered caps from Digi-key; will let you know how it comes out...

[lrwebb]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

There are three led's on the main board; one comes on then goes out the other two blink on and off. Can someone tell me what each is suppose to indicate and is there different indications ???

[veikra]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

any reason why a electrolytic instead of the tantalum or ceramic wouldnt work for a quick test? I have 2 boards, one from a lcd 40 inch and one from a 50 inch plasma. Both have same issue, the plasma one had the cpu reflowed in 2015.

[veikra]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

capacitor probably not my problem

I have 1.7ohm short circuit on standby power and standby ground. that, on BOTH similar board. Removed DDX chip on one, short still the same on both board.

Any troubleshoot beyond that ?

[goldmund]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Wanted to say thanks to everyone who contributed to figuring this out. Just finished repairing my TV with almost zero soldering experience beforehand. Hardest part of the process was getting this beast off of and back onto the wall!

[jyoo]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Hello. I see a lot of successful fixes for the PN50A550 with the C102 capacitor. I searched online for same clicking issue for PN50B650 model but no results. The main board on the PN50B650 is different from the PN50A550 and there is no C102. Anyone have any luck with pinpointing the bad part on the PN50B650 model? Thank you!

[tom66]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

B650 is definitely different. Suggest you create a new thread for it.