Experiencing random Shutdowns/Sleep on MacBook.

[Samarium]

Hello everyone, I have been experiencing random sleeps after turning on my MacBook or after waking it up. I enter the password, and sleeps again, upon the 5th intent, it shut's down. This has passed two times in the last 12 hrs. Is this a hard disk failure?

 

[merl1n]

Hello everyone, I have been experiencing random sleeps after turning on my MacBook or after waking it up. I enter the password, and sleeps again, upon the 5th intent, it shut's down. This has passed two times in the last 12 hrs. Is this a hard disk failure?

Are you sure you are entering the correct password? Is your caps lock on as passwords are case sensitive.

 

[Samarium]

Yes, I enter the password correctly, it enters into my user after a second it sleeps.

 

[merl1n]

Yes, I enter the password correctly, it enters into my user after a second it sleeps.

I don't think this is a hardware failure, but something wrong with the OS.

What I would do and in this order:

1. SMC reset
2. PRAM reset
3. Safe Boot and login
4. Download the 10.5.3 combo updater from here...
http://www.apple.com/downloads/macosx/apple/macosx_updates/macosx1053comboupdate.html
5. Run Disk Utility and repair permissions
6. Apply the combo updater (even if you already applied 10.5.3 using Software Update)
7. After the reboot(s), repeat step 5

See if that fixes your problem. Report back please.