Apple Event: May 7th at 7 am PT
Yosemite installed fine, closed laptop for the night. Next morning, black screen but computer appears to be at login screen. Pressing power button shows garbled login screen momentarily then goes back to black. I've heard that Yosemite has uncovered hardware flaws in older macs. I'm trying to revert to Mavericks but booting to USB doesn't appear to be working. Any help is greatly appreciated.
MacBook Pro, OS X Yosemite (10.10.5)
This is what flashes momentarily on the screen when I press the power button in the black screen/powered on state. Once in awhile, I can make out the login screen.
I hope your data is backed up.
i would try this first:
Reset the SMC and the NVRAM:
https://support.apple.com/en-us/HT201295
https://support.apple.com/en-us/HT204063
Then try a safe boot:
https://support.apple.com/en-us/HT201262
If there is no change, see if you can boot into the recovery partition (COMMAND + R keys).
Try to reinstall the OSX.
Try and run the Apple Hardware Test. Use the original install disk that came with the MBP with the AHT instructions written on it. Note that an reeror free AHT is not definitive.
If available, connect it to a monitor. If the monitor displays the same as the MBP, the GPU is suspect. If the monitor shows a good image, the display or the display connection is suspect.
Ciao.
Thanks for the reply.
I've already attempted resetting SMC and NVRAM. Holding shift for Safe Boot has no effect. I've got a bootable USB made for Mavericks which seems to start the boot process (screen stays black) while the light on the thumb drive blinks as if there is some activity but I can't get anywhere without seeing what's on the screen and it seems to just hang. I don't have install disks as I bought the computer used and it only came with the power cord. I haven't tried the monitor aspect as I don't have one handy. I'll give that a try as soon as possible and report back.
If you have an Apple store nearby, make an appointment. The evaluations at the genius bars a FREE and that would be a good place to define the problem.
Duplicate installation disks can be obtained from Apple Customer Service. They can be useful in situations that you are currently dealing with.
Ciao.
Looks to be the display. Hooking up an external monitor appears to be functioning fine while the main display remains dark or shows the garbled mess in the screenshot above. Advise on what may be wrong with the display. I've read a few things (don't remember where) where Yosemite reveals a hardware issue that mavericks or something earlier didn't have a problem with. Would reverting back to an earlier OS possibly solve my issue or do I just admit defeat and use my hobbled macbook pro as a glorified desktop now?
I mentioned the display criteria in the last paragraph of my initial response. A display replacement will be expensive, a display connection problem will be much less so. I do not believe reinstalling a prior OSX will solve the problem, but you may try.
I still would encourage a trip to an Apple store genius bar for a definitive evaluation of the problem. Powerbookmedic.com and iFixit.com both have parts and instructions how to replace the display or the connection.
Ciao.
2009 Macbook Pro - Black Screen Boot
