Перейти к основному содержанию

Samsung UN55KU6500FXZA no standby light, but has power

I have a UN55KU6500FXZA Samsung TV that will not turn on. When plugged in there is no standby light, but the backlight comes on. If I press the power button the standby light will blink but nothing else happens. The power board tests out fine as best I can tell so I replaced the main board. There was no change in performance. I then replaced the power board and still no change. I noticed if I unplugged and replugged the LVDS cables that I could sometimes get the standby light on and the screen would quickly show SmartTV before turning off and reverting to no picture and no standby light. I then replaced the LVDS cables and that didn't change anything. Hoping that someone has an idea as to what else I should try or any ideas on fixing this. Thank you in advance.

Block Image

Ответ на этот вопрос У меня та же проблема

Это хороший вопрос?

Оценка 0
Добавить комментарий

1 ответ

Наиболее полезный ответ

Hi @overtonk

Just confirming that when the power is connected to the TV that the backlights turn on and stay on, is this correct?

Since you have replaced the power board and the mainboard, I would check that the cable between the mainboard and the power board is OK.

Can't zoom in far enough on images of the power board online but there should be a pin marked PS-On on the power board cable connector where the mainboard cable connects to. There may be a STBY pin as well but maybe not.

What happens is that when power is first applied to the TV a Standby (STBY) signal voltage (usually 7.5V but can be 11.0V or even 5V - should be marked on the power board) is sent to the mainboard from the power board and it is the mainboard that turns the red standby power LED on.

When the TV is turned on the signal (earth?) that was on the PS_On lead is removed and this turns the power board on, full power so that there's the sufficient power being supplied to operate the TV. This includes the backlights.

So if the TV backlights turn on immediately the power is connected, there was no signal being received from the mainboard to keep them off until the TV was turned on. Also no signal was being received by the mainboard to turn on the red standby power LED

Был ли этот ответ полезен?

Оценка 1

6 Комментариев:

Hello @jayeff, let me start by saying thank you very much for trying to help me. I really appreciate it. I added a picture of the relevant part of the power board. I checked the cable and from a continuity standpoint it seems fine. I cannot see the PS-On pin, which is why I added the picture. In my testing of CNM803 I am seeing 12-13V from pins 3, 5, 7, 9 and about 3V from pins 2, 4, 6. Pin 8 was 4.5V. I also checked the middle leads of DM854C and DM853C, which I believe the board suggests is STBY 8V or 13V and I am getting no voltage. This is the same on both power boards I have so it might be that my replacement board is also bad?

из

@overtonk

It might be that the replacement is also bad.

The STBY reference point is 8V and this should change to 13V when the TV is turned on.

Is it 13V with the cable removed?

Removing the mainboard - power board cable can be used on selected Samsungs (not all were wired the same way) as a quick test to see if the backlights were working in the case of no video - sound OK problems etc, i.e. if standby light OK, then with cable removed, the standby light is off and backlights should be on all the time, not off or blinking etc.

That's why I suggested checking the cable since both boards had been replaced.

из

Hello @jayeff, I cannot get voltage for the STBY (middle leads of DM854C and DM853C) no matter what. Whether the main - power board cable is plugged in or not, it is still 0V. That backlights remain on all the time, whether the main - power board cable is plugged in or not. I'm thinking my replacement is bad.

из

@overtonk

I agree.

Hopefully you can get a refund or a replacement for nothing from the seller.

Cheers

из

I am reaching out now. Thank you again. I will let you know what happens.

из

Показать 1 больше комментариев

Добавить комментарий

Добавьте свой ответ

Keith будет вечно благодарен.
Просмотр статистики:

За последние 24часов: 0

За последние 7 дней: 0

За последние 30 дней: 0

За всё время: 124