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Old 08-12-2017, 09:16 AM   #21
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

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Originally Posted by tom66 View Post
Don't jumper fuses. Easy way to destroy wiring harnesses or potentially damage the panel in this instance. (Panel is fed by 5V supply for address drivers.)
This is probably a good idea. I shouldn't chance damaging the components because I want to find out now if this is indeed the issue. I'll patiently wait for the delivery of the fuse. Once I've received and installed it, I'll report back. If there is anything else I should check in the meantime, please let me know.
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Old 08-19-2017, 01:54 PM   #22
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

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Both of the LEDs are green, I doubt they will have failed, I think normally only one flashes and the other is always lit but I can't be sure.

The fuse is a Littelfuse 451 surface mount fuse. I'd expect ~5V both sides of it.

You can test the power supply without the control board but right now I'd be more interested to see if or why the control board isn't firing up the power supply.
So I finally have an update. It took me awhile to receive the fuse. Once I had it, I went to Lowes to get some rosin flux and thin 63/37 solder. Lo and behold, all they had was acid flux and only one choice of thick 60/40 electrical solder. So I had to place another order from Amazon for the solder and flux. Not sure where a DIYer is supposed to get this stuff after Radio Shack stopped being a tinkerers paradise and eventually closed up.

Anyways, I got the old fuse removed and installed the new one. My soldering skills aren't the greatest, but I got the job done. At F2000 I now get 5.3V on both sides. The green LED on the logic board now turns on.

But, a powered logic board didn't seem to solve my problem. Upon plugging the TV in, I get a click, the green LED now illuminates on the logic board, steady for about 3 seconds and then it goes to slow blink. I still get the flashing red LED on the front with no effect coming from hitting the power on button. The only change I see after installing the new fuse is the logic board is now getting the 5.3V and the green LED illuminates.

I once again isolated the motherboard and ran the logic board pattern test. Upon plugging the TV in, I get a single clicking sound, the green LED illuminates steady for about 3 seconds, and then goes to a slow blink. There is no picture on the screen.

I have been plugging the TV in while monitoring Vs. It does not rise or jump over 5V.

The only change in behavior I get is when I unplug the ribbon cable from the Y-sus board. When I do that, I get a continuous clicking noise, and Vs will rise to about 15V. The logic board continues its steady blinking green light, and no picture appears.

No other combination of unplugged ribbon or power cables does anything. Even with both the Y-sus and X-sus boards unplugged, Vs does not get to the specified voltage when plugging the TV in.

Any ideas on where to go from here? Thank You!
Attached Images
File Type: jpg Logic Board Fuse Removed.JPG (1.16 MB, 7 views)
File Type: jpg Logic Board Fuse Install.JPG (690.2 KB, 9 views)
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Old 08-19-2017, 03:11 PM   #23
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

I would say that the Y-main may be at fault. Slow blink indicates a fault with the sustain parts.
Try checking VS ON signal.
Also may be worth checking the Y-main for shorted transistors.
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Old 08-19-2017, 03:45 PM   #24
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

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I would say that the Y-main may be at fault. Slow blink indicates a fault with the sustain parts.
Try checking VS ON signal.
Also may be worth checking the Y-main for shorted transistors.
I'm guessing you mean to check Vs_On where the connector for the power supply to logic board is. Am I correct? And when do I check Vs_On, what should I expect to see? Is there a way to short or kick a signal through Vs_On to see if it would work? As in verifying if the PS is operating properly. Also, what is Vs_Con?

From what was written earlier in the thread, I thought even if the sustain boards were bad, you would see Vs at the proper voltage during the first 3 seconds of plugging the TV in. I may be incorrectly interpreting what I read.

I'll pull the Y-sus tomorrow and look at the back side. Maybe there will be some sort of obvious issue or short.
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Old 08-20-2017, 02:03 PM   #25
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

Vs-on should go high when the Vs output is on, or when the control board is trying to turn it on.

Don't jumper Vs-on for now, it could be a bad idea if there is a fault.

You might not see good Vs if there is a short, or a short circuit behind other components that only gets enabled when certain transistors are switched by the control board, this could be e.g. the energy recovery circuit which only starts switching when the panel is sustained.
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Old 08-22-2017, 01:31 AM   #26
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

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Vs-on should go high when the Vs output is on, or when the control board is trying to turn it on.

Don't jumper Vs-on for now, it could be a bad idea if there is a fault.

You might not see good Vs if there is a short, or a short circuit behind other components that only gets enabled when certain transistors are switched by the control board, this could be e.g. the energy recovery circuit which only starts switching when the panel is sustained.
So, for the pin labeled Vs_On from the PS to logic board, I get 3.2V when the TV is plugged in. It is only for 1 second at most and than quickly drops to 0V. I still haven't bought a quality multi-meter, so I don't know if there is any lag involved. I would think not since the other 5V pins jump to 5.3V almost instantly.

Vs never climbs higher than approximately 6-7V when plugged in.

I've gone ahead and ordered a returnable Y-sus board in the meantime. Hopefully I'll receive it in the next few days and swap it out. If there is no change in behavior, I'll return it.
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Old 08-22-2017, 01:34 AM   #27
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

It seems like your power board may be at fault. Vs-on is a 3.3V logic signal generated by the control CPU; it should go to ~3V when Vs is on, but Vs is not rising for one reason or another.

Try checking all fuses on the power board - sometimes the Vs ckt has a separate fuse. Also, check Va.
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Old 08-22-2017, 02:04 AM   #28
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

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It seems like your power board may be at fault. Vs-on is a 3.3V logic signal generated by the control CPU; it should go to ~3V when Vs is on, but Vs is not rising for one reason or another.

Try checking all fuses on the power board - sometimes the Vs ckt has a separate fuse. Also, check Va.
I get 0V at Va at plug in, and it does not change over time.

All three fuses I marked in the attached photo have continuity. If I have missed any, let me know and I will check them.
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File Type: jpg Power Supply Fuse Check.JPG (752.8 KB, 17 views)
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Old 08-22-2017, 02:05 AM   #29
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

Looks like you got all of them.

What voltage do you get across any of the large 5 capacitors above the fuse while the TV is switched on in the test pattern mode.

Note: they are all in parallel so need only test one. Careful, it's the high voltage side. Be careful not to slip probes or you may blow fuses or cause further damage to PSU. (Unlikely to damage other boards, though. But it would make a right old bang!)
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Old 08-22-2017, 02:17 AM   #30
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

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Looks like you got all of them.

What voltage do you get across any of the large 5 capacitors above the fuse while the TV is switched on in the test pattern mode.

Note: they are all in parallel so need only test one. Careful, it's the high voltage side. Be careful not to slip probes or you may blow fuses or cause further damage to PSU. (Unlikely to damage other boards, though. But it would make a right old bang!)
Those are pretty high voltage. I had to crank the multi-meter range to the top end!

If the capacitors outlined in red in the attachment are the ones you wanted me to test, they move between 375V-389V.
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File Type: jpg Power Supply Capacitor Check.JPG (753.8 KB, 13 views)
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Old 08-22-2017, 02:37 AM   #31
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

Ok, that's good, it means the PFC booster is working (390V nominal)
With both X and Y disconnected from the PSU, check Vs now.
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Old 08-22-2017, 10:46 AM   #32
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

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Ok, that's good, it means the PFC booster is working (390V nominal)
With both X and Y disconnected from the PSU, check Vs now.
When I have both the X-sus and Y-sus disconnected from the PSU, I see Vs at 6V when the TV is plugged in. At initial plug in, I get a single click. If I also disconnect the ribbon cables, I get a continuous clicking and Vs will rise to about 13V until the clicking stops.

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Old 08-22-2017, 12:14 PM   #33
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

OK, this is almost certainly a power board fault then.

If you have an oscilloscope, we might be able to check a few things.

Otherwise, I'd suggest replacing the power board.

It *may* be worth exchanging the two blue caps in the centre of the power board - the ones that are rectangular. These can fail and cause this type of symptom. It's vital you use the right type of capacitor so if you want to go this route, get me a pic of the capacitors and the dimensions (width, height, spacing between pins) and I'll look for a suitable replacement.

Last edited by tom66; 08-22-2017 at 12:15 PM..
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Old 08-22-2017, 02:11 PM   #34
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

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OK, this is almost certainly a power board fault then.

If you have an oscilloscope, we might be able to check a few things.

Otherwise, I'd suggest replacing the power board.

It *may* be worth exchanging the two blue caps in the centre of the power board - the ones that are rectangular. These can fail and cause this type of symptom. It's vital you use the right type of capacitor so if you want to go this route, get me a pic of the capacitors and the dimensions (width, height, spacing between pins) and I'll look for a suitable replacement.
Unfortunately, I do not have an oscilloscope. I'll ask around and see if any of my friends may have one, but I have my doubts about it.

The capacitors are 14.3mm wide x 17.5mm long x 8.5mm deep. The spacing between the pins is 15.0mm. I've attached photos of the capacitors.

I do have a capacitance tester. Is it worth removing them to test? My only concern is getting them in and out without damage. I imagine I can snip their leads off and solder them back on there. This way I'm not fighting to keep solder hot at two locations on the board to try and get them out. Also, it appears they are marked as 33nJ. Why would it be in Joules instead of Farads?

I am wondering since my PSU board is suspect, is it worth just sending off to PTS electronics? It looks like they have a repair and return option for $68. That seems like a pretty reasonable price. This is the link to their site: http://www.ptselectronicsinc.com/bn44-00447a/ .

And since I have a Y-sus on the way, should I swap it out and try anyway? Or just leave it be and return it.

Thanks.
Attached Images
File Type: jpg Capacitor Top View.jpg (169.1 KB, 21 views)
File Type: jpg Capacitor Side View.jpg (677.5 KB, 15 views)

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Old 08-23-2017, 08:07 AM   #35
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

Up to you if you want to try and repair it or send it off. For that type of capacitor I'd suggest removing it completely rather than snipping leads. They can be desoldered by alternating the soldering iron between both pins while gently prising it off the other side. If there's any glue surrounding it (white blobs tacking it down), remove that first.

The "J" simply refers to the tolerance of the capacitor, J meaning 10%. They are 33nF capacitors. A joule rating would be meaningless as it would depend on the voltage across the capacitor. You can test the capacitors for capacitance, though ESR is not a useful measurement. They will be small in value.

As it is, your new Y-main will do nothing as your Vs is too low. There might be several faults on this TV if it was subject to power surge damage or something of that nature. So might be worth hanging onto that board for a bit before you return it, just in case.
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Old 08-23-2017, 11:57 AM   #36
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

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Up to you if you want to try and repair it or send it off. For that type of capacitor I'd suggest removing it completely rather than snipping leads. They can be desoldered by alternating the soldering iron between both pins while gently prising it off the other side. If there's any glue surrounding it (white blobs tacking it down), remove that first.

The "J" simply refers to the tolerance of the capacitor, J meaning 10%. They are 33nF capacitors. A joule rating would be meaningless as it would depend on the voltage across the capacitor. You can test the capacitors for capacitance, though ESR is not a useful measurement. They will be small in value.

As it is, your new Y-main will do nothing as your Vs is too low. There might be several faults on this TV if it was subject to power surge damage or something of that nature. So might be worth hanging onto that board for a bit before you return it, just in case.
I guess I can give swapping the capacitors a shot and see what happens. If that doesn't fix it, I'll put the original ones back in and send it to PTS. I spent some time looking around for direct equivalents. I imagine I need to stick with the film capacitor. It seems Digi-Key has quite a few options, but only one is actually stocked. Everything else I saw has a lead time of weeks. Is this one an acceptable replacement?

https://www.digikey.com/product-deta...132-ND/4157191

The only issue I see is that the seated height of 18mm may be too high. From my measurements, I need to be around 14.3mm. When I bend the leads and install it laying flat, it might bump into the little blue ceramic capacitor behind. Even so, I can install and test the capacitor to see if indeed that was the problem.

So just for clarification purposes, if I remove the main boards from the PSU, Vs should always temporarily rise to specified voltage when the TV is plugged in? And because this isn't happening, we can say with certainty that the PSU is not functioning correctly?
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Old 08-23-2017, 02:40 PM   #37
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

I would suggest this one. I think it should fit:

https://www.digikey.com/product-deta...142-ND/5414292

The Rubycon one might work, but it's a different type of capacitor and I'm not sure how it will perform. The capacitor is utilised as a coupling capacitor in a high-frequency, high-energy LLC resonant circuit. A lot of long words, but essentially means the capacitor needs to be rated for this type of operation (high pulse operation). LLC is used to reduce electromagnetic emissions, audible noise, and improve energy efficiency.

Make sure the capacitor is clear from other components.

Quote:
So just for clarification purposes, if I remove the main boards from the PSU, Vs should always temporarily rise to specified voltage when the TV is plugged in? And because this isn't happening, we can say with certainty that the PSU is not functioning correctly?
These D-series (2011) Samsung sets vary a little bit from the previous generations B/C series. They will detect a fault on the boards and shut down the power supply. This fault could be caused by, for instance, a missing Y-main. So you should get Vs briefly before the control board realises it's not able to sustain the plasma panel for one reason or another. This will cause it to shut down the driver circuits and Vs/Va.

Last edited by tom66; 08-23-2017 at 02:42 PM..
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Old 08-23-2017, 03:19 PM   #38
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

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I would suggest this one. I think it should fit:

https://www.digikey.com/product-deta...142-ND/5414292

The Rubycon one might work, but it's a different type of capacitor and I'm not sure how it will perform. The capacitor is utilised as a coupling capacitor in a high-frequency, high-energy LLC resonant circuit. A lot of long words, but essentially means the capacitor needs to be rated for this type of operation (high pulse operation). LLC is used to reduce electromagnetic emissions, audible noise, and improve energy efficiency.

Make sure the capacitor is clear from other components.
Would it be an issue that the capacitor on the board is rated 1250V, and the one you suggested is rated for 1000V? This is the problem I run into. Anything larger than 1000V doesn't seem to be kept in stock.
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Old 08-23-2017, 03:38 PM   #39
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

Unlikely to be an issue. The board operates on 390V (the PFC voltage) plus there will be some transients due to the LLC switching edges not being perfect, but still well under the 1000V rating.

At a guess, they used 1250V because it was the most economical price or was the only product available from a preferred vendor at the time.
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Old 08-23-2017, 04:40 PM   #40
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Default Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

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Unlikely to be an issue. The board operates on 390V (the PFC voltage) plus there will be some transients due to the LLC switching edges not being perfect, but still well under the 1000V rating.

At a guess, they used 1250V because it was the most economical price or was the only product available from a preferred vendor at the time.
Transients, LLC switching edges. This is getting into a realm of Engineering I do not know very well. I'm a structural Engineer by training. This sparky stuff gets way over my head. I'd have to do some reading to really understand what it all does. Sometimes I think I'd like to go back and get a graduate degree in Electrical Engineering.

Digikey seems to be pretty quick on shipping. Hopefully I receive the parts and install them by this weekend. If not, off to PTS electronics it goes.

Thanks again for all the help. It is much appreciated.
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