Question Old iMac problem


May 14, 2016
So, im in a bit of a weird situation. I have an iMac 2005 which was running ubuntu. So i wanted to change to POP!_os. I took the harddrive out, plugged in to my windows pc etc. the point is that the hard drive is fully functional with pop_os on my windows pc. However when i put it back in my iMac, it starts with a grey screen and displays a grey file with a question mark. After a few tries to get it to work( trying different software, different drive) without any success, it even stopped displaying tha file thingy. Is there anything i can do besides throwing it away?
If it is a 2005 iMac. That means it uses a PowerPC 970 or 970fx CPU. As far as I can tell Pop Os is x86 only. Also PowerPC Macs requires a disk formatted under an Apple Partition to be bootable. Which a standard PC won't be able to create.

You'll need to use a 10.3 Panther, 10.4 Tiger or 10.5 Leopard DVD to format the drive. Install OS X and then find a Linux Distro which is PowerPC compatible. Please note that for 10.3 and 10.4 compatibility may require a special installer disc. Check for your specific model to know exactly what the minimum version is. If it requires 10.3.5 for example 10.3.4 and earlier won't work.

Here's a popular thread for PowerPC Linux enthusiasts.