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Old 09-02-2019, 06:21 PM   #1
Rotorcraft230
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Default Samsung UN65MU6500FXZA won't turn on

hello all I hope someone can help me troubleshoot my TV. It's a 4K curved only 2 years old. The power supply is a BN44-00808E.

Symptoms:
Nothing happens when power button is hit. I opened up the back and have poked around and there is no voltage on the stand by pin on the power supply, but there is lots of other voltages that seen right but not for sure. If I unplug the connector going to the Main board the back light comes on, but as soon as I plug it back in the back light goes off. Nothing on the board looks bad. I'm suspecting there is a problem with the stand by circuit.

any help would be much appreciated

Thanks Mark
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Last edited by Rotorcraft230; 09-02-2019 at 06:26 PM..
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Old 09-02-2019, 06:43 PM   #2
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Default Re: Samsung UN65MU6500FXZA won't turn on

Trying to post pictures
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Last edited by Rotorcraft230; 09-02-2019 at 06:49 PM..
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Old 09-02-2019, 06:52 PM   #3
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Default Re: Samsung UN65MU6500FXZA won't turn on

Here are some pics of the power supply. The bar that says stay pwr is zero if this helps

Thanks Mark
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Old 09-02-2019, 06:59 PM   #4
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Default Re: Samsung UN65MU6500FXZA won't turn on

Seems like a faulty mainboard, do test 3 below, try to do it just like instructed.
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(Signature) One of the first and least expensive things you can do when you have an issue is take the powerboard out of the tv, flip it over and look the solder joints over with a magnifying glass if needed, add a little flux to make the solder flow well and add solder to any joints that look even a little suspect. You can practice on a scrap pcb board if needed, careful not to bridge any joints, and always let the board sit for quite a while or discharge the big caps with an appropriate resister before working on it (safety first) to try to keep from getting shocked, it doesn't take 1000 volts to KILL, a lot less can kill, so be careful, it's only a tv.
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Old 09-02-2019, 07:03 PM   #5
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Default Re: Samsung UN65MU6500FXZA won't turn on

Means your main board isn't returning PSon to the PSU. Main board problem. Does the PWR LED light up on the front, you hit the power button and nothing is happening? May be a bad EEPROM on the main board.

Symptoms EEPROM replacement MAY fix:
- On screen display is stuck on logo screen
- TV won’t power on with remote or buttons (LED indicator remains same color)
- TV won’t turn on after being off for 30+ minutes
- TV shuts off by itself during channel scan or when switching inputs
- TV turns on and is stuck in color test pattern mode forever
- TV turns on but there is no backlight (LED indicator shows TV is on but there is no image)
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Old 09-02-2019, 07:09 PM   #6
Rotorcraft230
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Default Re: Samsung UN65MU6500FXZA won't turn on

Hello nomoresonys and CapLeaker, thanks for the replys I will do test 3. And CapLeaker there is no power LED when I hit the power button that I can see. I am not that familiar with this TV I am trying to help a friend. Where is the light located. I will go and do the test for you nomoresonys.
Mark
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Old 09-02-2019, 07:22 PM   #7
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Default Re: Samsung UN65MU6500FXZA won't turn on

I see that you have backlights etc. with the main dissconnected so the power supply must be ok.

Last edited by R_J; 09-02-2019 at 07:36 PM..
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Old 09-02-2019, 07:26 PM   #8
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Default Re: Samsung UN65MU6500FXZA won't turn on

o.k. no power LED, then check the PSU first as per R J. If you know that power goes to the main board, then you need a main board replacement. The EEPROM will NOT fix your problem. The LED should be located at the bottom right underneath a bit recessed to the back. You should feel a "bump". Basically look under the TV bottom right.

Last edited by CapLeaker; 09-02-2019 at 07:30 PM..
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Old 09-02-2019, 07:26 PM   #9
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Default Re: Samsung UN65MU6500FXZA won't turn on

Hi R_J j807 is 9.66VDC. the one above that is 0VDC
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Old 09-02-2019, 07:37 PM   #10
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Default Re: Samsung UN65MU6500FXZA won't turn on

Pin #
1 FAIL COUNT 0
2 ANA-DIM 0
3 A13V 9.67
4 OD ON/OFF 0
5 A13V 9.67
6 BLU_PWM 0
7 A13V 9.67
8 POWER_ON/OFF .103
9 A13V 9.67
10 GND 0
11 GND 0
12 GND 0

All these measurements were the same with power button not activated and activated.

thanks Mark
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Old 09-02-2019, 07:41 PM   #11
R_J
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Default Re: Samsung UN65MU6500FXZA won't turn on

Is that J807 9.66 volts with the mainboard connected or not? It should be around 7.5v in standby and then go up to 11.8v with Power_on/off (or with the main board disconnected)
I suspect the 9.66 is the standby voltage, so if you are not seeing the Power_on/off line voltage change when you push the power button, your fault IS on the man board and it could be a faulty eeprom, Shopjimmy does have them available so it can be the problem. (If you order one, get the correct one for your board)

Last edited by R_J; 09-02-2019 at 07:48 PM..
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Old 09-02-2019, 07:45 PM   #12
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Default Re: Samsung UN65MU6500FXZA won't turn on

R_J, j807 is 9.67 with everything connected. if I disconnect the main board connector it goes to 12.84 and the back light comes on.
Mark
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Old 09-02-2019, 07:49 PM   #13
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Default Re: Samsung UN65MU6500FXZA won't turn on

Ok, then that power supply is working like it should.
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Old 09-02-2019, 07:56 PM   #14
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Default Re: Samsung UN65MU6500FXZA won't turn on

I just want to confirm which board is bad before I buy one.
Mark
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Old 09-02-2019, 08:24 PM   #15
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Default Re: Samsung UN65MU6500FXZA won't turn on

This might be it, try to match the BNxxx numbers on the white sticker on your mainboard or just contact them with your board details, they can tell you if it's a match: https://www.ebay.com/itm/Samsung-65-...oAAOSwKs1dUfd6

Last edited by nomoresonys; 09-02-2019 at 08:26 PM..
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Old 09-02-2019, 08:31 PM   #16
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Default Re: Samsung UN65MU6500FXZA won't turn on

Hey thanks nomoresonys. There are lots in EBay the one you found isnít the same one my TV has but I appreciate you spending the time looking.
I just was wanting some guidance on diagnosing. Sounds like a main board problem. Here is the one from my TV
Attached Images
File Type: jpg 02B11BAC-4BBC-4492-A691-3B59C6011249.jpg (479.5 KB, 28 views)
File Type: jpg 438678F9-B03F-46E6-AA76-7DCE5B343B71.jpg (482.6 KB, 15 views)
File Type: jpg 38CDF64A-6916-4635-8670-EF913C7DDBFD.jpg (630.2 KB, 16 views)
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Old 09-02-2019, 08:32 PM   #17
nomoresonys
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Default Re: Samsung UN65MU6500FXZA won't turn on

BN94-12428A and BN94-11709A will both work.
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Old 09-02-2019, 08:34 PM   #18
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Default Re: Samsung UN65MU6500FXZA won't turn on

Ah sweet. I will shop for either one
Thanks nomoresonys!!
Mark
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Old 09-02-2019, 08:39 PM   #19
nomoresonys
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Default Re: Samsung UN65MU6500FXZA won't turn on

Quote:
Originally Posted by Rotorcraft230 View Post
Hey thanks nomoresonys. There are lots in EBay the one you found isn’t the same one my TV has but I appreciate you spending the time looking.
I just was wanting some guidance on diagnosing. Sounds like a main board problem. Here is the one from my TV
.

Last edited by nomoresonys; 09-02-2019 at 08:40 PM..
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Old 09-02-2019, 08:41 PM   #20
nomoresonys
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Default Re: Samsung UN65MU6500FXZA won't turn on

Quote:
Originally Posted by Rotorcraft230 View Post
Ah sweet. I will shop for either one
Thanks nomoresonys!!
Mark
That IS the one you need, done this many many time, I would not steer you wrong.

Last edited by nomoresonys; 09-02-2019 at 08:43 PM..
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