Macbook pro 2009 screen goes black at login

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Level 4

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Macbook pro 2009 screen goes black at login

Does anyone have advice for this problem? e.g. is it hardware causing software corruption causing hardware problems or software causing hardware problems?

The past few days a new problem has cropped up with my Macbook Pro Mid 2009 (MacBookPro 5,5) computer. Something keeps getting corrupted to make the screen go black at the "login". It doesn't matter if I boot to the internal SSD or the external SSD, after booting up with the gray screen and apple and sprocket once it gets to the login it goes black. It's definitely booted into the account, because the caps lock works. Also, if I plug it into the external display, the external display works.

I've been able to intermittently get the MBP screen to display properly by running a bunch of steps. Same steps different results. So I'm not sure what is actually working. Except that it does seem resetting the SMC, zapping the pram, and clearing all caches seems to help more often than not. Repairing the Disk and file permission and rebuilding the directory seems to be less consistent. Deleting the System prefs com.apple.loginwindow.plist and com.apple.loginitems.plist also seems to sometimes have an effect but not consistently. I've tried booting into other user accounts and safe mode, but that does not work if the screen is already going black at login. There are no font issues.

I've been working with the current two discs for a few years now with no problems until Saturday. I replaced the battery a couple years ago and battery health is good.

I'm still looking for my original DVD's with the hardware tests to run.

So far, it seems like my options are to reinstall the software (I have a spare bootable external enclosure and SSD to test this with) or to create a new "user" to test it with.

The internal SSD is Mac OS 10.6 (because I need it for old software and backwards compatibility) and the external SSD is Mac OS 10.9 (because I need it with iOS 10 compatibility).

Does anyone have any advice or troubleshooting steps I should try?

Thanks!

MacBook Pro

Posted on Apr 26, 2021 11:38 PM

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Answer 1

Best reply

HWTech

Level 9

56,186 points

Apr 27, 2021 7:58 PM in response to Marlinespike

I cannot completely rule out a software issue, but the majority of times when the external display is fine and the built-in display has a problem, then there is a hardware issue with the built-in display. Even if it is OS or software related, the actual source of the problem could still be a hardware issue. This is very common with later models.

Perform a clean install of macOS (either to the internal or external drive) as this will help to confirm a hardware or software issue since you should not have any issues with a clean install (no restore/migration and no third party apps).

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Answer 2

Marlinespike Author

Level 4

1,897 points

Apr 27, 2021 7:23 PM in response to HWTech

Hi

Thanks for the reply.

The Macbook Pro built-in display does work.

It starts up normally, showing the Apple logo on the gray background and the sprocket, and either

as soon as it gets to the point where it logs in, it goes black, or,
the screen displays just fine, if it's plugged into an external display.

If I manage to do all the steps in whatever sequence is needed, the built in display works. It's working just fine now. And shows up in the display preferences. If I don't do all the steps in whatever order, the builtin display doesn't get "detected".

So whatever software or hardware problem it happens to be, it's not about the display. It displays just fine under the right circumstances.

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Answer 3

HWTech

Level 9

56,186 points

Apr 27, 2021 6:20 PM in response to Marlinespike

If the external display works, but the built-in display does not, then that usually indicates a problem with the built-in display. I'm guessing the backlight may be bad. It could be a bad cable, but most likely a bad LCD Panel since moving the display will usually cause the backlight or video signal to turn on or off if the cable is bad (sometimes even a bad LCD Panel can be affected by moving the display so that does not always indicate a bad cable).

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Answer 4

Apr 27, 2021 6:46 PM in response to Marlinespike

My guess is probably since your MacBook display is 12 years old it might be time for an upgrade however you might be able to find parts on Ebay to replace it yourself as I have seen in older models its pretty simple to do so. Or you could contact Apple and they might be able to do something but my best bet would probably be an Authorized Retailer because they can do repairs Apple sometimes will refuse

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Macbook pro 2009 screen goes black at login

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