Samsung 50AU7172, only blinking red light

[norbiszoke]

Hello,

We have this set here in our shop that is not ginving sign of life besides red light that is blinking one time after pressing the button and nothing more... After detaching the mainboard from the PSU (this set has separate board thank god?! or not...) the backlight comes on. After reattaching nothing besides red light.... Can anyone from the forum help me here? Thank you in advance. Here's a link with images of the mainboard and the memory IC's that are on it.


Regards, Norbert!

[EazyBone]

Well sounds like BL and PSU to BL works. Should start measuring voltages from PSU to main and make sure they all present. Plus a picture of psu legend. Samsungs generally have a blink code, so how many blinks is red light doing.

[norbiszoke]

Well sounds like BL and PSU to BL works. Should start measuring voltages from PSU to main and make sure they all present. Plus a picture of psu legend. Samsungs generally have a blink code, so how many blinks is red light doing.

The red light blinks one time. At the other post where the MU series is discussed there was a post that the boot in one of the SPI chips is bad and thats when the one blink is occuring. But will measure the voltages in a sec.

[lotas]

Check this area, it looks like moisture has entered, check the HDMI and usb input lines for short and low resistance to ground, put a jumper and disconnect the lvds cable and check for startup without a panel.

In the MU series, if the spi firmware fails, then the TV is completely dead and the standby indicator does not even light up.

[norbiszoke]

Check this area, it looks like moisture has entered, check the HDMI and usb input lines for short and low resistance to ground, put a jumper and disconnect the lvds cable and check for startup without a panel.

In the MU series, if the spi firmware fails, then the TV is completely dead and the standby indicator does not even light up.

That are is just typical dust from carpet. I cleaned it up. The 13V from PSU and 3.3V standby are present on the board. The 3.3V is there to the 24c512 and the 25q40. The 1.8V and 3.3V are also there at the EMMC. Thre is no short on the USB and the HDMI inputs.

[norbiszoke]

Check this area, it looks like moisture has entered, check the HDMI and usb input lines for short and low resistance to ground, put a jumper and disconnect the lvds cable and check for startup without a panel.

In the MU series, if the spi firmware fails, then the TV is completely dead and the standby indicator does not even light up.

What do you mean by putting a jumper? I disconnected the LVDS connector but still the same simptop.

[lotas]

What do you mean by putting a jumper? I disconnected the LVDS connector but still the same simptop.

About this jumper.

[norbiszoke]

About this jumper.

Shorted those 2 pins with the LVDS cable out, but still one blink and nothing else happens.

[lotas]

So what diagonal do you have, 50 or 55? What is the panel number? There is a programmer, read all the dumps (3 pieces) ic503, ic501 and ic502 and post them here.

[norbiszoke]

So what diagonal do you have, 50 or 55? What is the panel number? There is a programmer, read all the dumps (3 pieces) ic503, ic501 and ic502 and post them here.

The TV is a 50" one. Here is the panel number and the number from the backside of the set.

[norbiszoke]

So what diagonal do you have, 50 or 55? What is the panel number? There is a programmer, read all the dumps (3 pieces) ic503, ic501 and ic502 and post them here.

I can read all 3 of them. I have an RT809H programmer.

[Diah]

the main boards photo you posted it belong to 55 size.... the 50 as the lable on the back should be the mainboards with this lable

[norbiszoke]

the main boards photo you posted it belong to 55 size.... the 50 as the lable on the back should be the mainboards with this lable

I get what you mean, the mainboard was not changed by us, maybe by warranty service or someone else changed the board before us.

[norbiszoke]

The TV is a 50" one. Here is the panel number and the number from the backside of the set.

So what diagonal do you have, 50 or 55? What is the panel number? There is a programmer, read all the dumps (3 pieces) ic503, ic501 and ic502 and post them here.

Here are the contents from the IC's 501-502-503. And sorry for taking up your time.

[Diah]

I get what you mean, the mainboard was not changed by us, maybe by warranty service or someone else changed the board before us.

warranty service will never replace 55 in 50.. no reason.... the questions have you ever seen this SET working !?.

[norbiszoke]

warranty service will never replace 55 in 50.. no reason.... the questions have you ever seen this SET working !?.

No I have not, it came to our shop like this. You can never know what happens here in Serbia.

[EazyBone]

warranty service will never replace 55 in 50.. no reason.... the questions have you ever seen this SET working !?.

I literally had warranty service replace 50 in MB like 2-3 weeks ago. The warranty guy came with a new panel and new MB/PSU combo. Tried panel, wasn't it and replaced the MB. Maybe in USA they will do smaller tv

[lotas]

Try experimenting with these dumps, dump, ic501 is very different.

[norbiszoke]

Try experimenting with these dumps, dump, ic501 is very different.

Will try tomorrow morning.

[Diah]

I literally had warranty service replace 50 in MB like 2-3 weeks ago. The warranty guy came with a new panel and new MB/PSU combo. Tried panel, wasn't it and replaced the MB. Maybe in USA they will do smaller tv

not good enough this worker... he forget to bring with the RC and the main cord