Backlight not working

Hello so I have a nintendo switch that was working fine. I replace the C type port because some pats were bent. After replacing the port the backlight is not working. Everything else works fine. I can see the screen with a flashlight and can dock at the tv. Maybe its the fuse? a cap? I really did some research but cant find were is the backlight area. I know the ribbon and conector location and they are fine. I test another screen that I know works fine.

Hi jesus,

here is the location of the backlight circuit.
I would check the diode and compare the values of the diode mode meassurement.

1 Like

Thank you so much for your replay that was fast.

Well maybe very noob to read the measurements. I put the black probe on ground and then I touch the other points. I also use the diode and touch the parts for measurements. I have very different readings but maybe am doing it wrong. This is a photo of my board.

Looks like U4C IC its chipped but againg maybe am doing the readings wrong and its another thing.
None of the caps are shorted.

For diode mode measurement put the red probe on ground and with the black probe You can check the pads for alike values.
The diode I would check direct in both directions. One direction should give a high value the other one a low value. The coil(?) I would check for continuity. If everything reads fine without shorts, it s possible that the little ic is internally damaged. I m not sure but it s a six or nine ball (b)ga ic and isn t hard to replace with hot air soldering.
I don t know the correct name of this ic. I would take it from a donor board.

1 Like

Thank you so much I will try that and update.

Why cant I upload pictures and links?

hey Calvin, im troubleshoooting a switch with a smiliar no backlight no lcd problem, im comparing to your values above and my values on the lower little left cap (670) are about 100 lower than yours, im about 60 lower on all the other caps, what does the lower value mean? should i replace the ic just to see if it works/?

The values in diode mode measurements depends on the used multimeter. If all measurements are around 60 lower in compare to mine, I would expect that they are fine. If a value is more than 100 off I would check it further. The both lower caps (670) left and right to the ic should show the same value.
I would give it a try with replacing the ic.

I know this is an old thread but I was just testing in diode mode. The circled one is coming up OL on multimeter. Does this suggest replacement chip needed?