Hello everyone. I ran into a problem with the backlight on the Switch Lite-no 17 volts. The components are all in order - I moved them from working to non-working and vice versa. Now I am interested in a specific question - where is the 17 V that should go from the inductor. I measured on the working one, they are only already on the capacitor that is next to the diode. In the photo, I marked everything. I read all the topics on problems with the backlight , I did not find an answer to my question
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https://www.ti.com/lit/ds/symlink/tps61163a.pdf?ts=1620688796425
check the backlight ic datasheet.
the inductor has 3.7~4.2v vin at bottom pin. Top pin is SW pin
17v goes to the cap next to the diode as well as the test pad from the top(red lines)
check the backlight ic datasheet.
the inductor has 3.7~4.2v vin at bottom pin. Top pin is SW pin
17v goes to the cap next to the diode as well as the test pad from the top(red lines)
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I would buzz through the 17v drive line through to the backlight FPC on the daughterboard. The connector linking the two boards is famous for burning out or losing connectivity at one end. Normally you get button faults at the same time which are a good indicator.
If the line is broken in any way, then the backlight IC will only output a few volts no the full 17v you expect. As jkyoho said the datasheet should have a lot of good information to help you on your journey.
If you have a known working unit you might want to try different combinations of boards to zero down to faults with the connectors linking the boards or the ribbon linking them etc.
Sheriff.
If the line is broken in any way, then the backlight IC will only output a few volts no the full 17v you expect. As jkyoho said the datasheet should have a lot of good information to help you on your journey.
If you have a known working unit you might want to try different combinations of boards to zero down to faults with the connectors linking the boards or the ribbon linking them etc.
Sheriff.
I second what he said, My lite had the backlight trace blown on the ribbon cable, What I did until I got a replacement was run a magnet wire from the main board to the left board to get the backlight working.
Hi. This is my first message in this group. Nice to see so many helpful comments.
I have a water damaged Switch Lite which I am having issues to get the back light working.
The digitizer and screen are working as per normal.
I have taken voltages from this damaged board and compared to a working board, while attached to a known working backlight, connecting ribbon cable and side board.
I noticed that the damaged board does not go up to 17V as it should. I have also swapped the BGA 9ball BL chip.
My noob question: Is the backlight dependent on any other component other than the BGA chip and this cluster?
I have a water damaged Switch Lite which I am having issues to get the back light working.
The digitizer and screen are working as per normal.
I have taken voltages from this damaged board and compared to a working board, while attached to a known working backlight, connecting ribbon cable and side board.
I noticed that the damaged board does not go up to 17V as it should. I have also swapped the BGA 9ball BL chip.
My noob question: Is the backlight dependent on any other component other than the BGA chip and this cluster?
Last edited by DinSg,
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The daughter board works fine when tested with a good board.
i have also taken the BGA chip from another board, which I know the backlight is working.
Made sure all the balls are good and transferred to this damaged board and still nothing. No 17v.
The output voltages where is it supposed to be at 17v are at Vin...
I also have transferred the BGA chip from board to board and all the backlights work, except for this board! Arghhhhh
i have also taken the BGA chip from another board, which I know the backlight is working.
Made sure all the balls are good and transferred to this damaged board and still nothing. No 17v.
The output voltages where is it supposed to be at 17v are at Vin...
I also have transferred the BGA chip from board to board and all the backlights work, except for this board! Arghhhhh
Last edited by DinSg,
I was replacing the joycon thumbsticks on nintendo switch lite. Everything was perfect. When I'm done I was trying to power the device on and Didn't power on. Then plug into charger it powered on. Opened it up and checked again everything was perfect. Closed everything back and backlight wasn't working. Brought home and checked under the microscope I was only seeing 4.3v instead of 17v. When I fold that flex ribbon between motherboard and sub board, Backlight came back. I ordered that flex and waiting for shipping. I found this forum when I was searching. This is the only source that I can find. Thanks guys it was helpful thread for diagnosing my problem. I'll give you guys update when I get that flex. It's really crazy that flex break that easy. Man I was about to give up and buy a customer new switch lite... I mostly do motherboard repair I wasn't gonna get that joycon replacement I knew something was gonna happen....
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I had a similar problem, but I replaced the connector twice, I was convinced it was perfect, but it was because I changed it again and the backlight came back on.
Assuming the backlight IC has an enabler pin, so that this chip wakes up and switches the inductor in order to boost voltage to ~17V, what enables it? Is it the APU? If it is, would you happen to know which pin is it and how many volts does it get to enable?
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My son had his switch damaged by another kid. Backlight issue as well. My question is as I troubleshoot the issue with my son's is there a way I can power on the backlight externally to do a data transfer to a new unit as I trouble shoot this one any suggestions.
Can I ask u how did u measured? During the battery is connected??
I have 0 voltage at the Pont who should have 17v. I think therefore the ic should be damaged?
The screen itselfs works fine just the backlight didn’t work for me
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Sure you need to have battery in and turn it on when measuring the backlight voltage.
But since you don't have backlight, you should rather check diode reading（like here） on the backlight connector or continuity between long cable from mainboard to joycon/daughter board.
Thanks for your fast reply! First of all i would let you know that i am not a professional in this field and bought the defect switch as a kind of hobby
I measured the voltage with one pin on metal as gnd and the other one in the field (above them) and its smoked a bit
but the switch is working as well... just the backlight has the fault.Regarding the measurement on the daughter board i think it is necessary to have an microsokop or?
The attached pictures shows the cleaned backlight cable.. all of the conductor path works
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clearly water damage and this backlight cable is badThanks for your fast reply! First of all i would let you know that i am not a professional in this field and bought the defect switch as a kind of hobby
I measured the voltage with one pin on metal as gnd and the other one in the field (above them) and its smoked a bit
Regarding the measurement on the daughter board i think it is necessary to have an microsokop or?
The attached pictures shows the cleaned backlight cable.. all of the conductor path works
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If you have a giant round prob lead, avoiding short-out the pins next to each other around any connector, i.e backlight connector. You may end up leading high voltage(17v) short through the pwm or signal pin burn out the backlight driver chip(since you mentioned smoke).
You could measure the backlight reading from the trace I marked on each color.
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That's correct, unless you are capable to repair the broken traces on the cable.
I would just replace the entire LCD,because from experience you might end up having water mark left between LCD& backlight panel after you manage to repair the cable and everything.
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I assume you only having backlight issue.
check the backlight connector diode reading when battery and backlight cable disconnected.
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