Samsung 60" LED blank screen and WILL NOT STAY OFF

[x_orange90_x]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

That meter is not measuring proper voltage. That 222V is actually 160V, So it is reading aproximately 62 volts high. So the pfc boosted voltage would be 460v-62v= 398vdc
CM861 3622v-62v = 300v which is close to the 297vdc for the backlights
I don't under stand "Just tried to put it into Standby and it still won't" you just proved that it does.
This power supply also may require that the BLU_ON (cnm803 pin6) be connected to ground to turn off the backlights.

I have a hard time believing that it's off by 62v considering I checked the 16v cap yesterday at just under 16v.

As for the standby thing, the objective is to put it into standby and it stay there, isn't it? If I remove the jump it is instantly on again. If it comes right back on then it can't truly be in standby.

[R_J]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

That meter is not measuring proper voltage. That 222V is actually 160V, So it is reading aproximately 62 volts high. So the pfc boosted voltage would be 460v-62v= 398vdc
CM861 3622v-62v = 300v which is close to the 297vdc for the backlights
I don't under stand "Just tried to put it into Standby and it still won't" you just proved that it does.
This power supply also may require that the BLU_ON (cnm803 pin6) be connected to ground to turn off the backlights.

[x_orange90_x]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

This is just to check if the power supply can be turned off and is ok, this would then point to the main board as the likely problem. Just check the voltage across CP806 like you did before, it should be 160vdc. If the power supply is in its off state you should not have any voltage on CM861.
That auto sensing is likely auto ranging, so it picks the voltage range based on the voltage it sees. But these cheap meters are not ment for these type of circuits.

I have an LG/Goldstar meter that will show OL on the 1000vdc range when checking a plasma tv Vs voltage, my fluke checks it as 200vdc which is the correct voltage.

Just tried to put it into Standby and it still won't. If I have the backlights unplugged there is a constant hum from the board and when I jump JP825 to JP817 the hum goes away, but as soon I stop jumping then it hums again. If I leave the backlights plugged in, they stay solid on when I jump it, but immediately start flashing again after I stop jumping it.

I left it jumped and checked them. This is what I got:
CP806 = 222v
CM861 = 362v

[R_J]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

This is just to check if the power supply can be turned off and is ok, this would then point to the main board as the likely problem. Just check the voltage across CP806 like you did before, it should be 160vdc. If the power supply is in its off state you should not have any voltage on CM861.
That auto sensing is likely auto ranging, so it picks the voltage range based on the voltage it sees. But these cheap meters are not ment for these type of circuits.

I have an LG/Goldstar meter that will show OL on the 1000vdc range when checking a plasma tv Vs voltage, my fluke checks it as 200vdc which is the correct voltage.

[x_orange90_x]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

You can try forcing the power supply OFF by disconnecting the main board plug CNM803. then short JP825 (PS_ON) to JP817/JP818 (GROUND). this will take the PS_ON line low and should place the power supply in standby mode. Then you can check if the main filter voltage drops to 160vdc
This would also confirm that the meter reads this voltage correctly. That 460v-480v on cp806 should be 380vdc. I would say it is your meter that can't reject the high switching frequency signal of the pfc boost circuit, thats why it is reading high.
Same for CM861 = 475v - 500v, This voltage is BOOSTED at high frequency by the led boost circuit, so it also is reading high.

So after getting it into standby you want me to check the voltages of all three of the caps again?

Don't know if it matters but this is an Auto Sensing meter.

[R_J]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

You can try forcing the power supply OFF by disconnecting the main board plug CNM803. then short JP825 (PS_ON) to JP817/JP818 (GROUND). this will take the PS_ON line low and should place the power supply in standby mode. Then you can check if the main filter voltage drops to 160vdc
This would also confirm that the meter reads this voltage correctly. That 460v-480v on cp806 should be 380vdc. I would say it is your meter that can't reject the high switching frequency signal of the pfc boost circuit, thats why it is reading high.
Same for CM861 = 475v - 500v, This voltage is BOOSTED at high frequency by the led boost circuit, so it also is reading high.

[nomoresonys]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

You could try heating or cooling the eeprom (IC901) with a hairdryer or freeze spray/upside down can of duster, wait 15 seconds or so plug tv in, power on and see if it comes on even for a short while or anything changes.

[nomoresonys]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

Not sure if there's a way to reset your model, there's some eeproms there if that's the problem, some whole mainboards boards too, as always make sure you check the numbers on the white sticker to ensure you get a match if you buy a mainboared: https://www.ebay.com/sch/i.html?_fro...acat=0&_sop=15

[x_orange90_x]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

what is the full model number?

un60fh6003fxza

[nomoresonys]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

What is the full model number?

[nomoresonys]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

Maybe you can reset the eeprom??

[x_orange90_x]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

Turn the TV off and check the Voltage on that cap again to see what is shown on the meter.

By turning it off you mean leave it plugged in but powered off, correct? If that's the case then I can't... Part of the original problem is that it WILL NOT stay off. It turns right back on within a second. Also turns on immediately upon plugging it in.

[budm]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

Every cap was measured between legs. The main plug was measured with a ground screw.

Edit:
Checked again, still got 460v-480v on it. I also checked WITH backlights plugged in and flashing and got 159v with drops every time it flashed.

Turn the TV off and check the Voltage on that cap again to see what is shown on the meter.

[R_J]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

Maybe that's the problem, the pfc circuit is going into over voltage protection.

[x_orange90_x]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

"CP806 = 460v - 480v"
What did you use for meter ground?
No way you can have 480VDC on that 450V rating cap. The Voltage MEASURED BETWEEN THE TWO LEGS OF THE CAP should be around 380VDC, the PFC circuit would have gone into shutdown if the Voltage really that high.

Every cap was measured between legs. The main plug was measured with a ground screw.

Edit:
Checked again, still got 460v-480v on it. I also checked WITH backlights plugged in and flashing and got 159v with drops every time it flashed.

[budm]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

"CP806 = 460v - 480v"
What did you use for meter ground?
No way you can have 480VDC on that 450V rating cap. The Voltage MEASURED BETWEEN THE TWO LEGS OF THE CAP should be around 380VDC, the PFC circuit would have gone into shutdown if the Voltage really that high.

[x_orange90_x]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

the "aa battery test" isn't going to do much other than trying to understand what happened with your meter. IF you aren't reading proper low voltage then, yes, give up on the meter. But if your other meter is broken, I wouldn't necessarily jump to the conclusion that its the answer unless you do some test trial before hand.

I got the other meter working and successfully checked the cap voltage on the TV. I will post all of the results when I'm finished.

Edit:

Here are the readings. I checked these with power on and the backlights UNPLUGGED. I tried checking with the backlights but obviously the voltages were erratic due to the flashing on and off.

1. B13V = 11.66v
2. PWM DIM = 1.67v
3. B13V = 11.62v
4. B13V = 11.6v
5. Vamp = 11.55v
6. BLU ON = 5.32v
7.Vamp = 11.46v
8. GND
9. GND
10. GND
11. B5V = 5.7v
12. A5V = 5.66v
13. B5V = 5.63v
14. PS ON = 4.06v

Caps:

CP806 = 460v - 480v
CM853 = 11.65v
CM861 = 475v - 500v

[budwich]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

the "aa battery test" isn't going to do much other than trying to understand what happened with your meter. IF you aren't reading proper low voltage then, yes, give up on the meter. But if your other meter is broken, I wouldn't necessarily jump to the conclusion that its the answer unless you do some test trial before hand.

[x_orange90_x]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

ok... so with the new 9v battery in, what does your "AA battery test" now read?

No way in hell I'm using that meter again. I'm going to try and get my old Micronta working.

BTW it had the new battery in it when I checked the AA and when it sparked on the PSU. I think it's just junk now.

[x_orange90_x]

Re: Samsung 60" LED blank screen and WILL NOT STAY OFF

I have NEVER had any multimeter cause a spark of any kind when checking voltage. What would be the point of having a multimeter for checking voltage if when you connected it, it created a short circuit creating a spark, across the voltage you are trying to check. The multimeter is defective.

I think you're correct. I haven't used it in about a year but last time I did it worked ok.

Anyways, I replaced the fuse and it works again, so I'm back to where I was before the big bang. Unplug backlights and watch for image on screen, plug in backlights and screen flashes. Also, just let it sit flashing for a minute and the screen got progressively darker. Seems like there's a big under voltage happening.

I have another multimeter, but it's not turning on. I'm going to try and get it working and see if I can get the readings you asked for earlier.