apple logo not appearing at grey boot screen

[pagardur]

Sometimes, when I turn on my iMac (10.6.2), the system will not load, you can see the grey screen but empty, no apple logo there. I have to force a shutdown pressing the power button and when I turn it on for the second time it will work properly.

It only happens once in a while but I cannot understand why, since nothing changes. Any ideas?

Thanks.

PS.- I have verified my disk with the disk utility and everything seems fine.

 

[bmcgonag]

Sometimes, when I turn on my iMac (10.6.2), the system will not load, you can see the grey screen but empty, no apple logo there. I have to force a shutdown pressing the power button and when I turn it on for the second time it will work properly.

It only happens once in a while but I cannot understand why, since nothing changes. Any ideas?

Thanks.

PS.- I have verified my disk with the disk utility and everything seems fine.

Do you have any external usb drives attached?

I've noticed mine does the same thing...usually it will finally go to the apple logo, but sometimes I have to unplug my usb drives, then it will go onto the apple logo and boot.

 

[pagardur]

Yes, I have a very simple USB external drive (LaCie) that I dedicate to TimeMachine. I have actually thought of it being the cause a couple of times, but didn't establish the connection in the end because the problem does not always appear, only sometimes.

So, in your opinion is the external drive most probably? Sort of the iMac getting confused about which volume should it use to boot?

 

[bmcgonag]

Yes, I have a very simple USB external drive (LaCie) that I dedicate to TimeMachine. I have actually thought of it being the cause a couple of times, but didn't establish the connection in the end because the problem does not always appear, only sometimes.

So, in your opinion is the external drive most probably? Sort of the iMac getting confused about which volume should it use to boot?

I'm not sure it's confused about which one to boot from, because this happens when I've had time-machine volumes attached, but also, when I've had a 1TB media drive attached which has no boot volume on it.

Just an odd thing about the system that i've noticed since Leopard, and now occasionally in Snow Leopard.

Wish I had a better explanation for you.

 

[pagardur]

Thank you so much. It's good to know that is probably a software problem instead of a hardware one.