RaezorSharp
Member
Hi,
I received a 820-2915 15" 2011 board that had the gMux hardwired to bypass the external AMD chip and was asked to do the gMux firmware update that allows brightness control. Upon removing the several wires that are involved in the bypass, I was able to reprogram the gMux using DosDude's firmware update but now the display is not showing a backlight.
Looked at BKL_PWM fail and I've checked R9704 is 33ohms, R9693 is 100k ohms, C9704 is not shorted to ground.
Also checked Pin 2 on U9701 (LP8550) that enable is 3.3V
BKL_PWM is only 8.8 mV, so I hard wired BKL_PWM to 3.3V and still no backlight
Also checked Output on PPVOUT_S0_LCDBKLT is only set to 12.5v,
I've reballed U9701 hoping to resolve some poor connection on the pads but no difference, should I assume the Backlight IC is toast?
I received a 820-2915 15" 2011 board that had the gMux hardwired to bypass the external AMD chip and was asked to do the gMux firmware update that allows brightness control. Upon removing the several wires that are involved in the bypass, I was able to reprogram the gMux using DosDude's firmware update but now the display is not showing a backlight.
Looked at BKL_PWM fail and I've checked R9704 is 33ohms, R9693 is 100k ohms, C9704 is not shorted to ground.
Also checked Pin 2 on U9701 (LP8550) that enable is 3.3V
BKL_PWM is only 8.8 mV, so I hard wired BKL_PWM to 3.3V and still no backlight
Also checked Output on PPVOUT_S0_LCDBKLT is only set to 12.5v,
I've reballed U9701 hoping to resolve some poor connection on the pads but no difference, should I assume the Backlight IC is toast?