iMac G3 Restoration Problems... We Apologize for Being Dumb

Hey there! Jacob here from www.superpolli.com with a bit of an issue. I'm working on restoring an iMac G3 from Summer 2000. I've replaced the RAM upgrading from below 256 MB of RAM to 1 GB of RAM. Today I attempted to replace the hard drive. I formatted a new hard drive and cloned the old one onto the new one using my Mac mini (2011 model in case you are interested, see all of my tech tools here.) After installing the drive in the iMac and attempting a boot, it failed. The iMac first showed a "No Disk" screen, then a bright white screen, then nothing. Before I could unplug it, the computer shut down. I gave it a minute and tried to boot. Nothing. I opened the iMac again and was greeted with a burst of hot air. After reinstalling the old hard drive, I put it back together and got a 100% successful boot! My question to you: What did I do wrong when setting up the drive? Does anyone actually know? Why did the iMac shut off after showing the "No Disk" screen? Some help here would be great as I'd love to make this a machine for playing music in my home office without clogging my Mac mini.