backlight goes out at end of boot sequence

[faithie999]

HP Envy 15t, i7-k000, i7-4710HQ, HD4600, Sierra 10.12.4

last night I closed the lid to put the laptop to sleep. after several minutes, sleep had not kicked in. I opened the lid and the screen was black. I pressed a few keys, pressed the power button, but to no avail.

I forced power off, then rebooted. the apple logo and progress bar appeared, but near the end of the boot sequence the backlight went out. I logged in from another computer using screen sharing, opened displays preference panel, and verified that the brightness slider was set to max.

I re-ran the kext installation portion of rehabman's envy installation guide but still no backlight.

booting into safe mode, the backlight works properly.

attached are troubleshooting files.

thanks in advance for any help.

 

[RehabMan]

HP Envy 15t, i7-k000, i7-4710HQ, HD4600, Sierra 10.12.4

last night I closed the lid to put the laptop to sleep. after several minutes, sleep had not kicked in. I opened the lid and the screen was black. I pressed a few keys, pressed the power button, but to no avail.

I forced power off, then rebooted. the apple logo and progress bar appeared, but near the end of the boot sequence the backlight went out. I logged in from another computer using screen sharing, opened displays preference panel, and verified that the brightness slider was set to max.

I re-ran the kext installation portion of rehabman's envy installation guide but still no backlight.

booting into safe mode, the backlight works properly.

attached are troubleshooting files.

thanks in advance for any help.

Your backlight control is not implemented correctly.
Make sure you update to the latest content in the Envy repo.