Hi!
I recently bought a defective Switch from eBay to try and fix it. After fixing the initial problem (Battery was depleted and Switch would not charge. Fixed by replacing the BQ24193 charge controller), it now mainly seems to work fine. However, the screen is really dim even on highest brightness to a point where dark writing is hard to read. The screen itself seems to work fine. See attached photo, the lower one is mine. Both are on max. brightness.
I am now wondering whether a replacement LCD would help or whether the problem is in the backlight driver/LCD driver.
I measured the voltages on the 4 pin backlight connector, referenced to battery ground. However, as I have nothing to compare them to, I do not know whether the voltages are where they should be...
Therefore, I hope that somebody here has his/her Switch already open and would be willing to measure the voltages. Could anybody be so kind, please? Thank you!
Here is what I got (from left to right with game card slot facing towards me):
Backlight on minimum (I am on Firmware 3.0.0): 245 mV - 15.79 V - 261 mV - GND
Backlight on maximum: 247 mV - 16.69 V - 270 mV - GND
I also checked with a scope and saw no signs of the backlight being PWM'ed. I also wonder why 3 pins + GND are used. Does anybody know what they are used for? Some sort of feedback?
Thanks again!
Kind regards,
Stefan
PS: Before replacing the BQ24193, I connected to it's I2C interface and read the registers with an external Raspberry Pi and a level shifter (after I found the STAT pin "blinking" when it should charge). Interestingly, it reported 0x04 in the fault register, which would mean "TS2 Hot". However, this is not even a code mentioned in the datasheet, as both TS1 and TS2 are shorted together in this IC and therefore should be asserted/deasserted at the same time, not individually... I wonder what happened to the controller to cause that...
I recently bought a defective Switch from eBay to try and fix it. After fixing the initial problem (Battery was depleted and Switch would not charge. Fixed by replacing the BQ24193 charge controller), it now mainly seems to work fine. However, the screen is really dim even on highest brightness to a point where dark writing is hard to read. The screen itself seems to work fine. See attached photo, the lower one is mine. Both are on max. brightness.
I am now wondering whether a replacement LCD would help or whether the problem is in the backlight driver/LCD driver.
I measured the voltages on the 4 pin backlight connector, referenced to battery ground. However, as I have nothing to compare them to, I do not know whether the voltages are where they should be...
Therefore, I hope that somebody here has his/her Switch already open and would be willing to measure the voltages. Could anybody be so kind, please? Thank you!
Here is what I got (from left to right with game card slot facing towards me):
Backlight on minimum (I am on Firmware 3.0.0): 245 mV - 15.79 V - 261 mV - GND
Backlight on maximum: 247 mV - 16.69 V - 270 mV - GND
I also checked with a scope and saw no signs of the backlight being PWM'ed. I also wonder why 3 pins + GND are used. Does anybody know what they are used for? Some sort of feedback?
Thanks again!
Kind regards,
Stefan
PS: Before replacing the BQ24193, I connected to it's I2C interface and read the registers with an external Raspberry Pi and a level shifter (after I found the STAT pin "blinking" when it should charge). Interestingly, it reported 0x04 in the fault register, which would mean "TS2 Hot". However, this is not even a code mentioned in the datasheet, as both TS1 and TS2 are shorted together in this IC and therefore should be asserted/deasserted at the same time, not individually... I wonder what happened to the controller to cause that...
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Last edited by StefanKrupop,