Samsung UN55D6005SF

[bleed4me]

Re: Samsung UN55D6005SF

Try having just the BL-ON wire disconnected and everything are back in place so you will get backlights, and if there is no other problem any where else then you should see image and sound and all other functions of the TV, if not then you have more than just no BL-ON signal.

Ok so BL-ON disconnected and everything back into place when i power on the TV it flashes the splash screen and turns off.
so no change on that...

I must ask though if BL-ON is already at a voltage of 0 why would disconnecting it make any difference?

[bleed4me]

Re: Samsung UN55D6005SF

Try having just the BL-ON wire disconnected and everything are back in place so you will get backlights, and if there is no other problem any where else then you should see image and sound and all other functions of the TV, if not then you have more than just no BL-ON signal.

The only way I can keep the backlights on is if the mainboard is disconnected from the power board.

[budm]

Re: Samsung UN55D6005SF

Ok so BL-ON disconnected and everything back into place when i power on the TV it flashes the splash screen and turns off.
so no change on that...

I must ask though if BL-ON is already at a voltage of 0 why would disconnecting it make any difference?

The BL-ON pin on the power supply board has pull-up resistors for performing power supply board self test, when the power supply board is connected to the main board, the main board will keep the BL-ON line low (<1V), when the TV is turned on then the main board allow the BL-ON to high turn on the backlights circuits.
So at this point you have more than just BL-ON problem on the main board some where. If you check the Voltages at the power supply connectors you will find that some other control Voltages are not there either.

[bleed4me]

Re: Samsung UN55D6005SF

The BL-ON pin on the power supply board has pull-up resistors for performing power supply board self test, when the power supply board is connected to the main board, the main board will keep the BL-ON line low (<1V), when the TV is turned on then the main board allow the BL-ON to high turn on the backlights circuits.
So at this point you have more than just BL-ON problem on the main board some where. If you check the Voltages at the power supply connectors you will find that some other control Voltages are not there either.

Thank you for explaining that! I never understood how that worked but it makes sense now. Much appreciated.

Does the PSON voltage need to be in the 5v range as well?

[budm]

Re: Samsung UN55D6005SF

PS-ON: <1V (typ.) = OFF, >2V (typ.) = ON

[bleed4me]

Re: Samsung UN55D6005SF

Ok so we at least know that voltage is correct. Which voltages am I missing here?

[budm]

Re: Samsung UN55D6005SF

Ok so we at least know that voltage is correct. Which voltages am I missing here?

You need to check the Voltages at the power supply connector pins that goes to the main board with connector in place but the BL-ON wire is not connected and see if they are all present or not, the chart is printed on the board.

[bleed4me]

Re: Samsung UN55D6005SF

Ok I just checkout out all the voltages on the powerboard with everything connected minus BL-ON and all the voltages are the exact same as when the BL-ON was connected.

[budm]

Re: Samsung UN55D6005SF

Are you saying you are getting exact same reading in post #5 or what? That is important info to be exact.
If you are getting the same readings then you need to disconnect the Dimming control line pin 10 (EPVW) also.
Your post #5 readings:
Power Supply
CNM803

Top
Pin 1 MC- not in use
Pin 2 B13V- 12.67v
Pin 3 B13V- 12.69v
Pin 4 VAMP- 18.5v
Pin 5 VAMP- 18.5v
Pin 6 GND- 0v
Pin 7 B5V- 5.3v
Pin 8 B5V-5.36v

Bottom
Pin9 MC- not in use
Pin 10 EPVW- 0v, At 0V there will be no backlights.
Pin 11 NC- 12.6v
Pin 12 BLU ON- 0v. it should show 2V or more at this point since the wire is not connected.
Pin 13 GND- 0v
Pin 14 GND- 0v
Pin 15 A5V- 5.3v
Pin 16 PSON- 3.3v

[nomoresonys]

Re: Samsung UN55D6005SF

.

[bleed4me]

Re: Samsung UN55D6005SF

Sorry it took so long for me to respond its been a day

So I have rechecked all voltages and they were all the exact same as post #5. I even replaced the batteries in my meter just in case and all the voltages were the same.

Now that Pin 10epvw is disconnected i now get the voltages you were looking for and the backlight stays on when the tv is powered on.

Top
Pin 1 MC- not in use
Pin 2 B13V- 12.67v
Pin 3 B13V- 12.69v
Pin 4 VAMP- 18.5v
Pin 5 VAMP- 18.5v
Pin 6 GND- 0v
Pin 7 B5V- 5.3v
Pin 8 B5V-5.36v

Bottom
Pin9 MC- not in use
Pin 10 EPVW- 3.2v
Pin 11 NC- 12.6v
Pin 12 BLU ON- 3v
Pin 13 GND- 0v
Pin 14 GND- 0v
Pin 15 A5V- 5.3v
Pin 16 PSON- 3.3v[/B][/I][/QUOTE]

[budm]

Re: Samsung UN55D6005SF

I expect the backlights to stay on when you also disconnect the EPVW wire, so we do have backlights but nothing is shown on the screen, correct, if that is the case then something is really bad on the main board.
Do you get switched 12VDC feeding the T-CON fuse?
If not you have lots of problem with this main board, I do not know the exact cause, may be bad EEPROM, FW, BGA issue, etc.

[bleed4me]

Re: Samsung UN55D6005SF

The screen will flash the splash logo then go to a dull lit grey screen.

When I check the voltage and fuse F102 on the T-con board i do get a voltage of 12.53.

[budm]

Re: Samsung UN55D6005SF

Good, so lets try again with having ribbon cable between T-CON and the LCD panel connected one at time to see what you will get, I want to see if you can get good half the screen and how long the image will stay on the screen.

[nomoresonys]

Re: Samsung UN55D6005SF

Tcon issue?

[bleed4me]

Re: Samsung UN55D6005SF

Ok please forgive the horrible pictures but when i disconnect the left tab and power on i get half the splash logo on the right but now on the left that is white vertical lines start to appear on the screen. Starts off as a single line and the longer it stays on the more that appear. If i disconnect the right side i get the exact same effects just opposite.

[nomoresonys]

Re: Samsung UN55D6005SF

Tcon issue?

No, seems like a bad mainboard, forgot I already suggested it in post #7.

[bleed4me]

Re: Samsung UN55D6005SF

So the question is just how bad is the mainboard and is it repairable?

[nomoresonys]

Re: Samsung UN55D6005SF

Some have but they are not near as easy to fix as powerboards imo.

[bleed4me]

Re: Samsung UN55D6005SF

Fingers crossed because the mainboard online is nowhere to be found.