Samsung PN50A510 P3FXZA Plasma Cycling On/Off

[bbsimons]

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

[trhouse]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Thanks to kevinm34232 for sharing the information that ModusLink replaced C102 a 47 mfd, 10V tantalum capacitor on the main board. Just did the fix to a Samsung LN46A0550P3 with main board BN41-0975C dated 2008-07-31. It worked.

Prior to replacement, I monitored the voltages from the power supply board; 5.1 volts (always on*), 13.8 volts (always on*), 5.1 volts (switched**), and 13.8 volts (switched**) with an oscilloscope. They were solid as a rock and never wavered until the relay (which connects up the hot side of the power line) turned off, shutting down the switched 5.1 and 13.8 volt supplies. The location of these voltages is silk-screened on the power supply board. Some of the bare jumpers are for these voltages which is easy to probe with a scope.

I then monitored the output of the Monolithic Power Systems MP2635 3.3 volt regulator with a scope. It was jumping up and down about 0.4 volt until the TV started to work. Then it settled down but was still bouncing up and down perhaps 0.1 volt. By comparison, the Monolithic Power Systems 1 volt regulator never moved at all.

After replacing C102, the 3.3 volts is solid just like the regulated 1 volt output.

* "always on" means as long as the TV is plugged into a live outlet, these voltages are present.
** "switched" means these voltage do not appear until the TV is turned on.

[EhBrah]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

OK who is the person that figured out this issue with the C102 cap?!!!!

edit: looks like it's kevin34232! Thanks for getting the information!


Thanks to this forum and discussion is was able to successfully repair my beloved TV!!!
I read through the comments and purchased a polymer Panasonic cap from Digikey. The part was only like $1.62 or something, shipping was $4.95 but the packaging was outstanding and treated as though I bought a hundred dollar part. I purchased two just incase since they're so cheap.

Prior to narrowing down the repair to this part I carefully inspected all boards and had no swollen or failed caps on the other boards so I unplugged/plugged in the boards until the ps started cycling, it would only do it when the mainboard was plugged in. That's what prompted me to perform this repair. I used one of the tips someone gave about holding the part down with tape and just soldering through it, worked great!

Thank you again whomever you are. I would buy you a nice drink, or two, or three if you are around San Francisco! Heck I'll send you one! hehe

[budm]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Hi I´ve PS42A450 with a cycle problem. The mainboard is a BN41-00982B.
But I cann not detect any tantal cap. Al the cap have numbers with 4 digits.
Like C2222.

Hope some can help me.

Pictures of both sides of the board?
BTW, you should start a new thread since your TV is not the same model as OP.

[toschi]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Hi I´ve PS42A450 with a cycle problem. The mainboard is a BN41-00982B.
But I cann not detect any tantal cap. Al the cap have numbers with 4 digits.
Like C2222.

Hope some can help me.

[MarkofCain]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Samsung PN58C550 with a cycling on/off problem

Thank you for all who have contributed to this thread. I want to let those know who are wondering if this might fix your set that this work for mine. The number of times to cycle on was growing by the day.

I ordered the parts and had them in my desk drawer. I actually ordered the suggested upgrade from Digi-key P/N 399-10532-1-ND @ $1.40 US

http://www.digikey.com/product-detai...2-1-ND/4246291

2 days ago, the TV would not cycle on -- even after 2 hours of cycling.

Pulled the back cover off, removed the board. Replaced C102 - Soldered it on. BOOM! Fixed and working like a brand new TV.

[rccrasher65]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Parts are coming today, fingers crossed that this fixes my problem, thanks guys!

Replaced C102, and Fixed. Thanks for all the info.

[rccrasher65]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Parts are coming today, fingers crossed that this fixes my problem, thanks guys!

[kc8adu]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

i had one recently that i actually pulled the relay out due to bad joints.
like it was in a socket!
good catch.
btw the nec/tokin polys have been problematic in other items too.
but here i suspect it was designed too close to absolute max for good long term reliability.
probably the obsolescence feature!

[lp20th]

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.

[rccrasher65]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

I have a Samsung PN50A550 with same symptoms as stated above, ordered new caps from Digikey. Will give this a try. Thanks for all info posted on this issue, was a great help. Will post results as soon as I get them in.

[72Tiger]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

The capacitors are definitely the issue. I'd change both C102 and C131. If you aren't comfortable with swapping them I offer a repair service on these on Ebay and have TVs here to check them out in.

Thanks for the info. I was able to repair by replacing the c-102 cap. It wasn't pretty but I was able to get it seated on the board albeit a bit cockeyed but it fired up and seems to be working just fine. I think my son was a little disappointed as he was already shopping for a new TV. Too bad for him, Thank you everyone for your help and great info.

[72Tiger]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Kevin...Just replaced c-102 on Samsung 50" plasma. Thanks for the great info on fix and source for parts. Seems like these TV's have a design flaw or a were manufactured with a batch of bad caps.

[Domain]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

The capacitors are definitely the issue. I'd change both C102 and C131. If you aren't comfortable with swapping them I offer a repair service on these on Ebay and have TVs here to check them out in.

where is c131 and the ratings? thank you

[aaronwt6]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Kevin, I have a Samsung Plasma mod. PN50A550S1FXZA with similar cycyling on and off and distorted picture. It's my sons TV he described it as turning off and on and after 10 minutes picture would come on. It has recently stopped coming on and keeps cycling with distorted picture. I replaced the Y-Sustain and Buffer modules without success and I am wondering if this could be a capacitor issue you have described in this thread. Any thoughts? Thanks Don

The capacitors are definitely the issue. I'd change both C102 and C131. If you aren't comfortable with swapping them I offer a repair service on these on Ebay and have TVs here to check them out in.

[72Tiger]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Kevin, I have a Samsung Plasma mod. PN50A550S1FXZA with similar cycyling on and off and distorted picture. It's my sons TV he described it as turning off and on and after 10 minutes picture would come on. It has recently stopped coming on and keeps cycling with distorted picture. I replaced the Y-Sustain and Buffer modules without success and I am wondering if this could be a capacitor issue you have described in this thread. Any thoughts? Thanks Don

[jpquesnel]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Hello all,
I am very grateful to this forum.
Ordered the cap from Digikey for $2.04 each. (bought a spare one)
Spent about 30 minutes, meanwhile, I also took the opportunity to clean the dust off the boards and heat sink.
Power up correctly the first time. It's like a new TV set.

Again, thank you every body for your post.

Cheers!

[ljintexas]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

http://www.shopjimmy.com/samsung-bn9...a510p3fxza.htm

[freakaftr8]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

Thanks for all this info. I had the cycling on & off problem & had the local TV repair shop replace bad caps last week (30 days warranty). But I still have the green snow problem until the TV warms up. Will take it back to them this week & tell them about the C102 try to get them to fix it.

Try reseating the lvds cable.

[ljintexas]

Re: Samsung PN50A510 P3FXZA Plasma Cycling On/Off

There is one 8 leg IC and one smd cap on the backside of the main board that causes the 3.3 volts for the cpu to fluctuate below 3 volts..produces audio squeal and distorted picture with vertical lines..heat main board up with a hair dryer..it will settle down.