Well, guess what came down my way? A 2011 27in iMac, it isn't mine to keep but rather it's for a client that I'm fixing it up (and hitting brick wall after brick wall in the process).
The symptoms? It doesn't boot at all, and the disk is making worrysome "spining rust thrashing" noises, so now I'm fighting the darn thing trying to clone it on a SSD. Or in theory, that's what I'm trying to acheive.
The reality? It doesn't even want to boot, it loads up to the "loading bar

" thingamabob then it just falls flat, belly up and shuts down.
Oh well, time to open that beast (it ain't light either, and I thought my G3 and my 2008 24in were heavy enough to be contenders!) and swap the hard drive for a SSD and call it a da-- Oh, right... Apple made the hard drives on these somewhat proprietary (to keep it short, the thermal sensor which on preceding iMac models would be glued to the drive's shell has been made internal, and it uses two normally unused* pins on the SATA_PWR connector) and I can't just swap the drive with a new one without having the fans go bananas... Unless I buy one of these OWC inline adapter cables. Oh Apple, what a dirty, dirty, dirty little trick. Tsk tsk tsk...
(*: unused?
Sort of. It was used in server backplanes to delay the drive startup, so all drives don't start all at once and overload the PSU's 12V rail with the inrush current)
I've ordered the OWC cable, at 40 euros it wasn't cheap, but since it's not my Mac, I'd rather have the tranquility of installing it and not having to rely on an app, besides, it's not my Mac, so... I had no other options 🤣
At least one good thing is that this iMac has a magnetic frame around the front glass, just like my A1225. Although the magnets on this one are much more stronger than they are on the A1225 (and my fingers can attest to that... ouch!)
Forgot to mention a few weeks ago I repaired its 21in cousin (I don't remember if this was a 2011 or a 2012), and that one had a glued-on glass panel... That one was fun, but at least it was a direct swap, just CCC'd the old HDD to the new SSD and off to the races it went! (opening that one up was fun... had to ask my father to open it up as he has more experience when it comes to prying open glued-shut iDevices LOL). Yet this one 27 is really putting up a hell of a fight.
iMacs, as beautiful they are, they can be a pain sometimes.