accessing old time capsule backups on new Mac

Time Machine, iMac, kitchen sink - to the internet thingy and plugging it all in to that, or will I be making things worse?

I am a bit lost what this means... I am guessing by internet thingy you are referring to the modem/router your ISP supplied??

A brand, model number and some details would help on that.

I might have failed to pick up the full meaning of your first post.

So let me start over.. step by step.

1) Assuming you plugged the Time Capsule (TC) into the back of the computer by ethernet it won't work without a reset. I am also assuming your computer is using wireless to the ISP router.

Please do a full reset of the TC. Hold in the reset button for 10sec until the LED on the front of the TC flashes rapidly. Release the reset and wait for the TC to fully boot again. About 2min.

NOTE> NO FILES ON THE HARD DISK ARE DELETED.

2) Open Airport utility.

Click on Other WiFi Devices (1)

You will see the Time Capsule identified as if fresh from the factory.. select it and the wizard will start.

Give the TC a simple name.. I suggest exactly following my example.. TCgen4 for both TC admin and wireless.

Use a simple short pure alphanumeric password.

Ignore the wan connection.. you don't need it.. just click next.

Wait for the setup to complete.. click done. Tell me if you have issues.

Now the TC should show up in the Airport Utility.. exactly as below.. with a bunch of errors which we can ignore. Ignore the flashing amber light. Makes no difference as we are extracting the backup only.

3) You can now click edit and plug in the USB and do the archive as I described above.

That might take a full day.. but you can just leave it run.. no intervention needed once started.

Once completed have another go opening the Time Machine backup in Time Machine.. You need to go to the Time Machine icon in the dock and right click it.

Select Browse other Time Machine disks.

Select the TC disk

You might find a range of disks and options.. you will need to find the right one.

If this works it should be easy to then use Time Machine to locate your files and restore them to the computer.

No luck we can try the next method.

I deleted everything that was still on it and emptied the trash, having failed completely to save my 30,000 word Masters dissertation from 2011.

Never ever trust time machine. Or any backup for that matter.. you should have had 100 copies on DVD and various hard disks and cloud.. you know that don't you?? Sorry but this deserves a rap over the knuckles.

Your old TC is in dangerous position.. you need to purchase a suitably sized (same size or larger than internal disk) mac formatted USB drive.. plug it into the TC. Open the airport utility.. locate the TC .. click the icon and click disk tab.. go to Archive disk. See on right just below the disk box..

Once you start the archive you can walk away for 12-24 hours for it to complete.

Once you have a copy of the backup.. reset the TC to factory..

This means hold in the reset and then plug in power while keeping reset pushed in.. and keep holding in for another 10sec.

Reconfigure the TC once it starts with Short names.. NOT APPLE RECOMMENDED NAMES.. no spaces and pure alphanumerics.

Passwords same rules but 8-20 characters or more if you are paranoid.

Now you can attempt to migrate your user files to the new Mac.. you cannot open the old backup from Time Machine.. especially if you are on Catalina... do try as I am known to make mistakes.. but don't be hopeful.

You can dig into the backup from Finder if you only need one file.. this is perhaps worth trying.. simply locate a date that matches when the thesis is on the computer.. and then select and try to copy and paste it.. worth a go at least.

There are more complicated methods but at least with archive you can mess around as you like.

Well 2TB or 3TB at least.. just a cheap portable USB type is fine. WD passport are usually fine.

Having yet another small drive .. 2TB are not a lot more than 1TB and well worth the extra could be worth it. In this case it would match the drive in your old iMac or larger.

I did not spell it out in my last post but we have successfully got people out of trouble by recreating their old boot drives.

In fact this is fairly easy if long procedure. Boot the Mac to recovery. Use Time Machine in recovery.. open the old Time Machine backup.. which will hopefully still work.. if the file/s you want were there when you wiped the old iMac you can use the last date.. otherwise go back to when you know the file was present.. and recover to your USB as the target drive. Don't write over your current boot drive in the new iMac.

Once you have recreated the boot drive you can either access it directly although you will have permissions issues or choose to boot from it.. which should still work. The later gives you exactly what the old iMac had, with everything identical.

Particularly if you are running Catalina latest patch, 10.15.5 we are getting lots of reports of issues with Time Machine.. so from that point of view don't try opening old backup in Catalina.. it is possible Catalina could mess it up..