Hardware Switch Backlight voltage?

[w0nk1]

I replaced a broken USB-C port and it is docking fine. But for any reason the backlight isn't turning on.

Then I measured the voltage at the backlight connector of my own switch and get around 14 volts if it's turned on.
The console where I am working on, shows just the standby voltage of around 4 volts.

What I can tell is, that the ribbon cable connector of the LCD seems to be a little bit damaged inside, but the display is working without the backlight (can see it under bright light). Is there any connection between the ribbon cable of the lcd and the backlight functionality?

Any ideas what could be the issue? Thanks for any help!

 

[linkinworm]

any damage to a ribbon cable = bad times, they are so thin its easy to break them, and impossible to really repair them

 

[w0nk1]

any damage to a ribbon cable = bad times, they are so thin its easy to break them, and impossible to really repair them

You mean the ribbon cable of the backlight connector? It worked before the usb-c repair. So i don't suspect the ribbon cable.

 

[linkinworm]

its possible you broke it during the repair , ribbon cables are as easy to rip as paper

 

[w0nk1]

its possible you broke it during the repair , ribbon cables are as easy to rip as paper

But should't I get the voltage despite of a broken cable at the connector itself?

 

[bombob]

If the connector is broken and pins are sorted ,you will not get the voltage

Sent from my SM-N960U using Tapatalk

 

[linkinworm]

maybe the connector is broke on the board? check the pins, and if the switch is smart it wont supply power if nothings connected in order to protect its self from frying stuff

 

[w0nk1]

Mhhh I have some irreparable motherboards laying around whre I could salvage the connector from.
Any idea how to proper desolder it?

 

[Ttm3]

On something like that I apply hot air from the other side of the board

 

[bombob]

Mhhh I have some irreparable motherboards laying around whre I could salvage the connector from.
Any idea how to proper desolder it?

Make sure its broken before attempting repair. Use low melt solder and a hot air station.Use kapton tape for the surrounding areas

Sent from my SM-N960U using Tapatalk

 

[w0nk1]

I swapped over the cases to confirm damgages and found out, that the repaired motherboard works fine with the other display/backlight.

So I attached the known "good" board in the other case and there is also a backlight issue.

What I've not seen during the previous attempts was, that the backlight lid up for aprox. 1 second and goes out immediately. :-/

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EDIT:
Guys I apologize! It was really the ribbon cable of the backlight which is broken! I could barely see it under the microscope, but it is damaged. I will try to repair it in some kind. Thanks!

 

[Ttm3]

I've actually had luck soldering those if it's a small enough break. But you have to be very careful

 

[w0nk1]

I was able to scrape some isolation off the cable and could tin it. Afterwards I soldered a piece of 0.15mm wire to it and it works like a charm!