UE40EH5000KXXU No power completely dead

[notallbad]

No power led at all!

Psu bd - BN44-00496A
Main bd - BN41-01795A
Key bd - BN41-01840B

Main CNM803
Pin 1 13v
Pin 2 0.08v
Pin 3 13v
Pin 4 13v
Pin 5 13v
Pin 6 4.86v
Pin 7 13v
Pin 8 0v
Pin 9 0v
Pin 10 0v
Pin 11 5.27v
Pin 12 5 27v
Pin 13 5.27v
Pin 14 3.37v

No change in voltages when pressing the power button.

Highly suspect the Main bd as theres no voltages present on the key bd (i.e power button/ir sensor/function buttons), theres no 3.3v.

[notallbad]

Re: UE40EH5000KXXU No power completely dead

PSU CNM803 Pinout

[neilc6]

Re: UE40EH5000KXXU No power completely dead

Looks like your tv is in an on state (pwr_on and bl_on) are both high. If you disconnect the cable between the main board and power supply board, do the backlights come on? If not suspect bad backlights. Seen lots of failures on EH model years. Front led not coming on may be a different problem.

[R_J]

Re: UE40EH5000KXXU No power completely dead

If you disconnect the cable between the main and power supply, and you don't have backlights, check the voltage on pin 6, BL ON/OFF, if it is around 5 volts, take that pin to ground and then your backlights should come on

[notallbad]

Re: UE40EH5000KXXU No power completely dead

Ok, yes. Get backlights come on by disconnecting the main bd. Around 3v on pin 6.

With main disconnected voltages read:
Main CNM803
Pin 1 13v
Pin 2 3.13v
Pin 3 13v
Pin 4 13v
Pin 5 13v
Pin 6 2.94v
Pin 7 13v
Pin 8 0v
Pin 9 0v
Pin 10 0v
Pin 11 5.27v
Pin 12 5 27v
Pin 13 5.27v
Pin 14 3.13v

[nomoresonys]

Re: UE40EH5000KXXU No power completely dead

That's a pretty good indicator that the mainboard is at fault.

[notallbad]

Re: UE40EH5000KXXU No power completely dead

Main bd connected and T-con disconnected still nothing.

Firmware corrupt?

[nomoresonys]

Re: UE40EH5000KXXU No power completely dead

You could try a firmware update but it looks like you need a menu on screen to do it: https://www.samsung.com/uk/support/t...sung-smart-tv/

[nomoresonys]

Re: UE40EH5000KXXU No power completely dead

Maybe try disconnect the power cord from the outlet, then press and hold the power button on the TV (not the remote), for 30 seconds. Then wait a few minutes and plug the TV back in and press power.

[nomoresonys]

Re: UE40EH5000KXXU No power completely dead

Could try mute-1-8-2-power, see if a menu comes up to try a reset.

[nomoresonys]

Re: UE40EH5000KXXU No power completely dead

Of course none of that will work if it's a hardware issue.

[notallbad]

Re: UE40EH5000KXXU No power completely dead

Theres no 3.3v to the key pad (ir sensor/power button etc...)

and believe theres no 5v to the USB port.

Will have to check for voltage at the CL slot but doubt that either.

Could try flashing/wiping the eprom 24c25.

[diif]

Re: UE40EH5000KXXU No power completely dead

These boards use a WT61P805 which is prone to failure shorting the 3.3v line.
Could be the reason you're not getting 3.3v to the key pad.
They need to be programmed. They are available on ebay https://www.ebay.co.uk/itm/WT61P805-...-/273573661006

[R_J]

Re: UE40EH5000KXXU No power completely dead

I think you are getting close, you should have 3.3v on the function board, I would check the regulators etc. It might be a shorted mlcc or open 0Ω/fuse somewhere on the main.

Or like diif stated above, a shorted ic.

[notallbad]

Re: UE40EH5000KXXU No power completely dead

If its the MT61P then replacing is not an option, don't have a heat gun and not sure I would successfully be able to do it anyway.
Perhaps I'll just wait to source a replacement main bd.

Though meanwhile,
Volt reg's
IC205 LD1117AG - 0.26v 1.5v 3.3v
IC707 LD1117AG - 0v 3.3v 5.2v
IC705_FN 9915-12 - 5.2v 0v 1.2v

[notallbad]

Re: UE40EH5000KXXU No power completely dead

Unable to locate any smd fuses on the main bd.

Also, if it were the WT61P805 shorted wouldn't there be voltage on pin 2? No voltage on the nearby crystal either!

Nor is there voltage on 25Q40BVSIP pin 8

[budm]

Re: UE40EH5000KXXU No power completely dead

https://www.badcaps.net/forum/attach...7&d=1567870374
Are you saying that none of the pins on the connector has any Voltage?

[notallbad]

Re: UE40EH5000KXXU No power completely dead

thats correct budm. no voltages on any of the keypad connector pins.

[R_J]

Re: UE40EH5000KXXU No power completely dead

I'm sure you should have voltage going to the keypad, I see you checked a few regulators but what about IC204 and IC201. what are there numbers and are they producing the voltage they should.

[notallbad]

Re: UE40EH5000KXXU No power completely dead

IC201 - Z1051Pi
Pin 1 0v
pin 2 5.24v
pin 3 0v
pin 4 0.8v
pin 5 0.83v
pin 6 4.75v
pin 7 1.84v
pin 8 1.11v

IC204 - Z1051Pi
pin 1 0v
pin 2 13v
pin 3 0v
pin 4 0.79v
pin 5 0.89v
pin 6 2.31v
pin 7 1.94v
pin 8 2.54v