No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600WRMXL

[nomoresonys]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

I suspect a backlight problem but I always do with led tvs.

[devbh]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

Does it click with ONLY the backlights unplugged?- yes it does click

I checked all 72 LEDs individually on both led strips using meter, all light up.

[nomoresonys]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

With everything hooked up, test the vdc of CP811S, should read about 160 then hit power should go up to 380 or so. positive probe on positive + leg, negative probe on negative - leg. be very careful as this is the HOT/DEADLY side of the board.

[budm]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

So if you do not have the power supply board connected to the main board, when you plug the TV into the AC outlet. How many times do you hear the black power relay RL801S click and what is the DC Voltage measured between the two legs of the main filter cap/s?

[devbh]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

The clicking repeats every few second or so.

Capacitor voltages:
Voltages at the 2 high voltage capacitors (CP811S and CP812S) are at 388v goes to around 344v on click sound and comes back
Voltages at C9831, C9832, C9817, C9818 are at 98v goes to around 91v on click sound.

[budm]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

If the relay is clicking when running the power supply board by itself then yon need to monitor the A5V and the PS-ON to see if it is changing in sync with the relay clicking of not since Relay runs on 5V and PS-ON turns on the relay.

[nomoresonys]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

1. with PB to MB cable unplugged and LED back light cables plugged, no clicking sound
2. with PB to MB cable unplugged and LED back light cables also unplugged, no clicking sound

Report was this.

[budm]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

It sounds like we are not getting the correct data which makes it difficult to do long distance troubleshooting.

[R_J]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

While watching the tv, distorted vertical colored lines appeared for few seconds and went away, it came back second time for few seconds and this time the TV blacked out with no audio no display

Has anyone cleaned the screen with a liquid (water) within the last few weeks? Try disconnecting the lvds cable between the main board and the t-con board, I suspect the panel board has liquid damage.

[devbh]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

Nomoresonys and budm, my apologies, for the incorrect info. In both cases i.e. with the LED cables plugged and unplugged along with PB to MB cable unplugged, the relay clicks only once and stays on after tv power cord is plugged.

I have taken all the voltages once again, please see the attached pic. Let me know what I can do further. Appreciate your help guys.

[nomoresonys]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

There's no reason the backlights shouldn't come on with a powerboard self test, makes me think backlight circuit issue, could be a loose connection in backlights, sometimes the leds don't show failure til they are driven with more current than by just testing one by one.

[R_J]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

You need to do is supply the backlight circuit with the proper PWM signals, OD_LE and OD_ON and then they should turn on.

[budm]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

You can pull the PWM pins high to simulate 100% full on, just do not do it for too long.

[devbh]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

how do I pull the PWM pins high to simulate 100% full on? The voltages that I am getting on the all the three connectors as per the pics sent, are they good? What should be the PWM signals, OD_LE and OD_ON voltages to lit the led strips?

[budm]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

Use a 1K resistor on each PWM pin and A5V pin, so you will need 4 resistors together, and no cable between main board and power supply board.
You can also read this Samsung Tech-talk to learn how Samsung does it without resistor when the board does not have pull-up resistors., I always use resistors in case the jumper is connected to the wrong pin.

[nomoresonys]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

Looking like the mainboard isn't sending pwm signals, guess next question is, is it something that can be fixed on component level or would it be better to just buy a replacement mainboard if that is the case?

[devbh]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

Shouldn't the backlight LEDs light up with power board to main board cable unplugged if the power supply board and LED strips are good? or Do we have to have the PWM signals from the main board for hte backlights LEDs to lightup?

[budm]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

You can pull the PWM pins high to simulate 100% full on, just do not do it for too long.

how do I pull the PWM pins high to simulate 100% full on? The voltages that I am getting on the all the three connectors as per the pics sent, are they good? What should be the PWM signals, OD_LE and OD_ON voltages to lit the led strips?

Use a 1K resistor on each PWM pin and A5V pin, so you will need 4 resistors together, and no cable between main board and power supply board.
You can also read this Samsung Tech-talk to learn how Samsung does it without resistor when the board does not have pull-up resistors., I always use resistors in case the jumper is connected to the wrong pin.

Shouldn't the backlight LEDs light up with power board to main board cable unplugged if the power supply board and LED strips are good? or Do we have to have the PWM signals from the main board for hte backlights LEDs to lightup?

PWM needs to be present for the backlights to be on that is why you need to use the resistors for each PWM pins. Did you not read the PDF?
I did the research and provide you the info, but you are not following through with it.

I also explained why you should use the resistors. I am wasting my times in this post.

Exert from PDF:
Testing the SMPS and Backlight Operation with No Main Board Connection
It‘s important to understand that disconnecting the Power Supply line to the Main Board and plugging in the AC Power Cord turns on the Power Supply circuits but does not light the Backlights in this model. Follow these steps to test the SMPS and Backlights:
1. With the AC Power Cord removed, disconnect the Power Supply Cable to the Main Board at the Main Board end.
2. Connect the AC Power Cord. This will turn on the SMPS Power Supply, but, because all four P-DIM Control Signals are at approximately 0V, there will be no Backlight LEDs lighting.
3. Check the four SMPS Backlight Power Supply Voltages at the four Electrolytic Capacitors: C9010, C9210, C9310 and 9410. They will have changed from 150VDC, the normal supply operation, to approx 95V VDC. The voltages may also begin fluctuating at each supply between 50-85VDC with the supply cycling on and off. This is also a nor-mal possibility in this condition.
4. Check the four backlight strings one at a time. Using an external wire jumper, locate and connect A5V to the P-DIM 1 control pins found on CNM803. This will light the left and right LEDs responsible for the top quarter of the screen.

[devbh]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

Please be assured that you are not wasting time. This is a great help for me. The PDF refers a different tv model/power supply and someone had mentioned that the LED backlights should turn on without the main board connected to the power supply board.

I will test with 1K resistors and report back. Thank you... appreciate your help.

[budm]

Re: No display, No audio, six times blinking Standby LED on Samsung LED TV UA40D6600W

All you had to do is to follow the instructions.