Tme Machine Problem?

[ConsiderPhlebas]

I have researched this but cannot find this particular issue with Time Machine and sleep mode.

In the past I only used time machine to back up my system only when there were major changes, new software, etc.

A few days ago I turned it on and left it on and now my iMac will immediately (within a second) wake back up when I put it to sleep even though Time Machine is not in operation. That is,TM is on but not performing any backups.

I understand it will not go to sleep if a backup is in operation, but shouldn’t it sleep if one is not? If this is not normal, how do I correct it?

BTW, I have a mid 2011 iMac 27 with intel i7, 8Gb memory, running SL 10.6.8 with backups to a WD MyBook 500 Gb USB external drive.

 

[lexvo]

After you put your iMac to sleep (and it turns on again immediately), have you tried to put it to sleep for a second time? I had this behavior on my previous iMac too and putting it again to sleep did the trick (BTW I never related this to TM, because I always have TM on).

Second, have you tried a SMC reset and a NVRAM/PRAM reset? (just a guess here, don't know if it will help but it will rule things out)

 

[ConsiderPhlebas]

(BTW I never related this to TM, because I always have TM on).

Thanks lexvo for your response and I think you are right about not related to TM. It does seem to be related however, to the external hard drive that I connected at the same time I turned TM on.

I tried turning TM off and ejecting the hard drive, ( leaving it physically connected), and my iMac still came back on immediately after putting it to sleep, and even though TM was off, the external drive was remounted since it was detected on power up.

The only way I can stay in sleep mode is to physically disconnect the external drive. Evidently there is some process the drive is using outside of TM that prevents sleep mode.

This probably has been the case since I got my iMac last May but I never noticed it before since I never left TM on and the usb drive connected.

Anyway, I now have a work around

 

[Brian33]

I had the same kind of problem after connecting the USB cable from my CyberPower UPS to my early 2008 iMac: I'd put the iMac to sleep, and in about a second it would wake up again. I even looked in the system logs using Console.app, and found messages indicating that a USB interrupt (or something similar) was causing the wake-up. I never could resolve the problem, so I have to do without the advertised UPS-initiated shutdown features.

Sounds like your USB drive is at fault. I wonder what brand and model it is?

 

[ConsiderPhlebas]

Sounds like your USB drive is at fault. I wonder what brand and model it is?

It's an old one. I have had it a few years and before I got the iMac I used it on my Windows PC. It's a WD 500H032. The Premium ES edition. There could be a problem with it I suppose but I don't have any problems reading from or writing to it.

 

[zhenya]

Connected external drives frequently cause problems with sleep, both on Macs and PC's. I suspect if you tried another drive, especially a newer one, you'd have no issue.