iMac shutdown strange

[Vyron]

I've seen several problems listing problems with iMacs randomly shutting down, but NONE like this.
My 21inch iMac arrived last week and it seemed to work fine. It had a lot of new stuff (I was using a 17 inch iMac that was 6-7 years old) I tried using the migration to transfer files, but because of some problem it didn't work. I had to use an Ethernet cable due to changes from the old to new.finally fished transferring files - no applications.
Then the new started shutting down the only way to get it started was to turn the old back on. So, I shut down the old iMacs wifi, air port an removed the Ethernet cable.
Here's the strange part . . . If I turn off the old iMac, the new one won't start. If I unplug the old computer, the ne one shuts down and won't restart.
It's like the new one is entirely dependent on the old one.
So, all you Mac gurus, what gives?

 

[DeltaMac]

Sounds like your new Mac is, somehow, set to boot using the hard drive in your OLD Mac.

Shut off your new iMac.
Make sure the old iMac is off and disconnected from the new iMac.

What exactly happens on the screen when you try to boot the new iMac now?

I suspect you will see a ?/flashing folder after a few seconds, meaning that your new iMac is improperly set for the startup drive. Wait it out - maybe up to 5 minutes, to see if your iMac eventually "finds itself"
If there's no change - restart, while holding Command-R. That will boot your recovery system, which is a hidden partition on your hard drive.
You'll get a menu with various choices, such as Disk Utility, and Safari.
Choose "Reinstall OS X", and continue on with a reinstall. It will NOT erase any data that you already have on the hard drive, but will reinstall your OS X system in place, replacing the system that is already there. It should take anywhere from 30 minutes, to an hour or more, then reboots at the end. That should take care of your booting issue.

 

[Crzwilly]

"It will NOT erase any data that you already have on the hard drive, but will reinstall your OS X system in place, replacing the system that is already there. It should take anywhere from 30 minutes, to an hour or more, then reboots at the end. That should take care of your booting issue."

This is why I love Mac.

 

[Vyron]

Nope

Well I have tried all suggestion and nothing has changed. The old shuts down and then the new. The new computer will NOT restart, even with holding down the cod-r keys. I did that anyway, redownloaded the software and got the same results. Why, when the old is off, disconnected, an in another room des the new refused to start???
Pretty soon I'm gonna have to call Apple or go to a store 100 miles down the road OR just pack it up and get my $1700 back. I've owned Macs since 1984 and I've never had any problem,
Please somebody, what gives???

 

[DeltaMac]

You say your new Mac won't restart.

What exactly does it do? Do you hear a boot chime?
If you don't hear a boot chime, does it make a difference if you try a PRAM reset? Hold the keys down for a minimum of two resets. That shouldn't take more than 15 or 20 seconds.

Does anything appear on the screen, even if just a blank white screen?

You probably should be able to hear the fans start up... Does that happen?

If anything else appears on the screen - describe what you see...

 

[Vyron]

Fixed . . . for now

Here's the latest.
I shutdown the new and unplugged it and took it to another room and used a different circuit. I restarted and the wife went to shutdown the old. Guess what? The new one did not automatically shut down. I turned it off Xander on several times wit no problems. Still don't understand, but things seem to work fine on different circuits. Whatever??? (But thanks).

 

[Vyron]

???w

Took new computer back to computer room and problem return. =scratching head.

 

[DeltaMac]

Took new computer back to computer room and problem return. =scratching head.

You still haven't told us what your new computer actually does.
Does it boot?
Do you ever see anything on the screen?
When you say "different circuit" - do you mean a different power circuit, or a different network connection (which is it?)

Your old computer should have a DIFFERENT network name, and a different IP address than your new one. It should, at least if your network is set for serving DHCP. You are not using the same static IP address on both Macs, are you? That's one main possibility that would cause a boot problem (but your OS X system should warn you that "there's another device using the same address"
Again, can you tell us what the new Mac actually does when you try to boot. Please give as many details about what happens, everything that you either see on the screen, or hear from the computer as it boots.

 

[Vyron]

Nothing

When the old and new are plugged into the same electric circuit the new computer will not turn on unless the old one is on first. In those circumstances, the old computer is off the new computer does nothing, will not boot, makes no sound, screen remains dark. When I bring the new computer into another room, it boots and everything runs great . . . Just like an Apple should!

 

[feuerdrache]

IMac shutdown strange

May be your old Computer is connected to a Master-Slave power Strip. Try the following: Plug the new one in the exact same socket where the old one is plugged.
Hope IT helps
Regards
Juergen

 

[poiihy]

May be your old Computer is connected to a Master-Slave power Strip. Try the following: Plug the new one in the exact same socket where the old one is plugged.
Hope IT helps
Regeres
Juergen

Master-Slave power strip? Waat? Such things exist?

 

[T'hain Esh Kelch]

Master-Slave power strip? Waat? Such things exist?

Absolutely. They are not uncommon and used to turn off several appliances when one specific one is turned on/off.

 

[Vyron]

Keep guessing

Each is plugged into its own power strip, but same room. Only connection I know of is the electric wire to the main switch box. But, good news is I'm slowly working things out. Slow, but sure!