Samsung UE32F6470 only red LED

[Grishnackh]

Hello Guys,

i have a Samsung UE32F6470 which does not turn on, only the red LED burn. It´s a BN44-00620A. I have tried to find some faulty capacitors, but everyone looks "normal". Are there any known components which are responsible for the defect?

Greets, Grishnackh

[budm]

Re: Samsung UE32F6470 only red LED

Pictures of the whole back side of the TV showing all the boards?
Do backlights come on if you disconnect the cable between the power supply board and the main board?
What Voltage checking have you done?

[CapLeaker]

Re: Samsung UE32F6470 only red LED

Check the PSON and BLon pins on the PSU.

[budm]

Re: Samsung UE32F6470 only red LED

BTW, shopjimmy does not have the pictures of the BN44-00620A so you you need to provide us good clear staright shot pictures of the top and the bottom side of the board for us.

[Grishnackh]

Re: Samsung UE32F6470 only red LED

Hello,

i have something tested. First, sorry but the red led turns on, flash two times and stay red, flash again, stay red and so on. This happens when PSU + Mainboard + Backlight + T-CON is connected. When i only connect the PSU + Backlight, the Backlight works. If i connect PSU + Mainboard + Backlight (without T-Con) it flash and stay red but the Backlight turns on for less then one second. I checked all the capacitors, but they all have the right values. I didnt check any voltage, where should i begin? Where are PSON and BLon pins on the PSU?
For now i have a picture from Top of the PSU and the back of the TV...i will soon upload the bottom of PSU.

Greets, Grishnackh

[CapLeaker]

Re: Samsung UE32F6470 only red LED

Pic #1 connector on the top that goes to the main board. BLU_on = Backlight, PS_on = power supply on. Check the DC voltage on those pins and all others too on that connector with the TV on.

[Grishnackh]

Re: Samsung UE32F6470 only red LED

Hello,

here are some values i measured. I found also a Russian Page http://www.kenotrontv.ru/forum/files...7-bn44-00620a/ with some reference values, however these do not fit with my PSU:-(

Greets, Grishnackh

[budm]

Re: Samsung UE32F6470 only red LED

'When i only connect the PSU + Backlight, the Backlight works.' So the power supply/LED driver combo board is fine.
All those readings you provided without the name of each pin do not help to find out what kind of signals/Voltages are missing.

[Grishnackh]

Re: Samsung UE32F6470 only red LED

Ah ok, sorry...i understand - i think you talk about this...

Greets, Grishnackh

[Moreno83]

Re: Samsung UE32F6470 only red LED

Measurements on the power supply look good. 10v is a little low , has to be something like 12.7v but that can be your meter.

[budm]

Re: Samsung UE32F6470 only red LED

https://www.badcaps.net/forum/attach...7&d=1468953789

Must be measurement errors because pin 7 & 9 are for B13V and you show 10V and 11.5V.
Pins 11 & 13 are Vamp and you are showing 10V and 0V.

[Grishnackh]

Re: Samsung UE32F6470 only red LED

Sorry, it was my mistake...at the moment i have this values

pin 7 & 9 -> 9,3V
Pins 11 & 13 -> 9,3V

Maybe the Voltage is to low for the mainboard, that´s why i didnt start?!

Greeets, Grishnackh

[Moreno83]

Re: Samsung UE32F6470 only red LED

Your meter is on volts DC right? Black prope on GND and red prope on pin 7 and you read 9.3v? Bit strange.

Disconnect the mainboard and turn on the tv. When the backlight is on , you still measure 9.3v?

[Grishnackh]

Re: Samsung UE32F6470 only red LED

Yes, DC Volt...thats right.
I only have the PSU connected to 230V, no mainboard and no backlight.

Greets, Grishnackh

[Moreno83]

Re: Samsung UE32F6470 only red LED

Ok thats a little low , normally its around 12.7 v.

Install the power supply and only connect the backlight cable. Leave the mainboard cable out of the PS and turn on the tv. ( connect it to 230v ). The backlight should come on. If not then your power supply or backlight is bad.

[Moreno83]

Re: Samsung UE32F6470 only red LED

Normally the LED in these tv's go bad. This model uses Edge-lit , They are connected in series like a christmas tree , if 1 goes bad the rest stops working.

[Grishnackh]

Re: Samsung UE32F6470 only red LED

Ok thats a little low , normally its around 12.7 v.

Install the power supply and only connect the backlight cable. Leave the mainboard cable out of the PS and turn on the tv. ( connect it to 230v ). The backlight should come on. If not then your power supply or backlight is bad.

Already done...fifth post..."When i only connect the PSU + Backlight, the Backlight works"

I dont know would i could be, it only could some IC i think....however i will continue the measure tomorrow...

Greets, Grishnackh

[ozzy214]

Re: Samsung UE32F6470 only red LED

BAd mainboard...mainboard not turning on psu. Look to see if pson signal from mainbord to psu when you hit the button. Should 3.3v

[CapLeaker]

Re: Samsung UE32F6470 only red LED

BAd mainboard...mainboard not turning on psu. Look to see if pson signal from mainbord to psu when you hit the button. Should 3.3v

Yes it is. See pic in post #9.
However the on/off pin is missing. PSon and BLUon is there.

Question is now do you get backlights with and without the mainboard attached? When the PSU is on, the DC voltage on the main filter capacitor is >360V?

[Moreno83]

Re: Samsung UE32F6470 only red LED

If the mainboard is bad then try to reflow the cpu under thst heatsink. It fixed my tv.