A1502 LCD no video on wakeup, backlight is on
I am trying to fix an early 2015 13" MBP.
Got it working (mostly) except on wake from sleep (or when rebooting during an install) I lose video output on the LCD. Backlight is on (verified by turning bringhtness all the way up, I get a light vertical display output from second lvds channel)
If I don't close the clamshell, use screen saver with "never sleep" timeout, it works fine (except needing hard power down if I update OS)
Unfortunately due to cats who love walking on keyboards, I need to close the lid.
I have tried:
- SMC and P/N VRAM reset
- unplug/replug battery (battery is "normal")
- safe mode
- booting external SSD (same problem)
- reinstalling OS
- googling many hours for answers
I suspect something with LCD voltage rails coming out of sleep, but I need to find the schematics and board view to check.
I will try an external hdmi monitor, which I suspect will work, but that does not help with getting sleep working.
Any/all help much appreciated,
Bill
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4 opmerkingen
External HDMI monitor works when clamshell is opened up.
door William Henning
Apple -> Restart reboots to blank LCD, external monitor works fine.
Apple -> Shutdown, then power on, LCD and monitor come up fine
I suppose I could disconnect the lid closed sensor, but that is less than ideal.
door William Henning
I suspect there must be an LVDS (eDP?) buffer that is being enabled by the SMC on cold startup, that is disabled when the lid is closed, and not being re-enabled properly by the SMC when waking up on lid opening.
door William Henning
@danj - You probably know the problem...
door Ben Capehart