Macbook constantly mutes itself after restart

Hello,

This is my first post as i'm still fairly new to the world of Apple.

First of all, I've got a 2010 macbook which i've been using for around 18 months problem free, until that i had only used Windows but don't hold that against me.

My problem now is that since i upgraded to Lion i seem to always be muted on start up. I can start the machine, look at the setting page for sound and the box will be ticked so i untick it and get sound, then i turn off when im done and the next time i start it i get the chime but when the desktop loads up and i check the sound again it's muted.

What i don't understand is why it's doing it but also if the machine was muted from the start i wouldn't hear the chime, would I?

The same also happens when i do a restart so it's not something that shutting down effects.

Any ideas? I've tried repairing permissions, running onyx and resetting the PRAM...

Hopefully someone will know what it is!

Try this: Open System Preferences, General. Go down to the area where it says "Number of recent items:" and remove the check (if it's there) in the box that states "Restore windows.............." Reboot.

Also make sure in System Preferences under Sound that you have removed the mute check from both the input and output options.

Right, i tried all that and still no joy.

Any more ideas? I'm beginning to wonder if i need to do a clean install?

Do you have any third party applications or startup logins items that are running? Check in System Preferences, Users & Groups, Login Items. Remove anything that might be causing the mute to come on.

The only startup items i have are HP software for my printer and the iTunes helper, should i try without them and see what happens?

I don't think either the HP software nor the iTunes helper would have anything to do with the mute being set, but it certainly wouldn't hurt to give it a try.

Well, i tried that and it hasn't worked either. It's really odd...

OK, let's try this: Reset the PRAM. PRAM stores many of the sound settings such as speaker volume and "beep". Who knows? Maybe it's stuck on mute. Anyway try the procedure and let us know.

That was one of the first things i tried because i'd heard that it can sometimes fix a few different problems.

Is your MacBook covered under Apple Care? If it is, it's time to take it in and have it looked at. Whatever is causing it to mute may be related to hardware although I still suspect that it may be due to software.

It's actually out of warranty but i've now solved it, i never got to the bottom of it even with the things people suggested so i decided to make sure my time capsule backup was up to date and performed a clean install of lion after making a bootable USB drive.

I then transferred my files manually and not just use the capsule backup to restore everything just in case. I've since put all my software back on as was and.....I have sound! w00t

Thanks for the suggestions!

Great, glad you solved it. Thanks for posting back and letting us know. Have fun and visit often.