I have an old MBP that refuses to see the HD in its normal slot , but I can boot from an HD in the optical drive slot using OSX 10.6.8. So far so good and it runs quite fast enough for my use , but if I put it to sleep it won't wake up. It won't respond to the power button either on a press or a hold. I have to power off and remove the battery to start it up again, and then it starts, switches itself off and then starts again and chimes. I have tried replacing the hall effect sensor for the sleep switch but the result is the same. One guess is that the computer needs to switch on the HD first and then the rest of the system follows on and without the HD in the main slot it hangs. Anyway , anyone else experienced this or can think of a solution?


My first thought would be to try and resolve the initial issue (i.e. the fact your MBP is not recognising the main drive slot), as that's what is most likely causing your current problem as well.

However, since you seem happy to work off the optical drive, I would try the following:

  1. First reset the NVRAM and SMC (in that order)1
  2. Boot up from the optical drive slot
  3. Go to Apple > System Preference > Startup Disk
  4. Ensure that the current boot drive is selected
  5. Exit System Preferences and Restart your MBP

Now test to see if that has made any difference.

1. Since you haven't provided details of your exact MBP model I've included links to Apple's instructions. Make sure you read these carefully so that you're following the correct steps for your MBP.

  • The hard drive in the caddy that is booting shows up in Disk Utility but not in Startup Disk selection in System Preferences. That only shows "Network Disk" with a ? and when I click on that it tells me "Unable to Bless bootable disk " – Oli Senior Sep 15 '18 at 11:18
  • So I guess I'll try to do that , I'm not very experienced using Terminal but will have a go . Sorry for lack of info- MBP 3,1 2.2GHz Core 2 Duo 4GB Ram. – Oli Senior Sep 15 '18 at 11:27
  • Interestingly , it shows the appropriate startup disk in About My Mac info , but not in Startup Disk Preferences – Oli Senior Sep 15 '18 at 11:30
  • Ok. Did you also reset both the NVRAM and SMC? Also, what condition is your battery in? Your MBP is a 2007 model, so if you've never replaced the battery you're going to run into a few power-related problems. Does the MBP run okay while connected only to AC power (i.e. without the battery inserted)? – Monomeeth Sep 16 '18 at 4:41

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