I may go insane. iMac G3 won't boot with IDE to SATA adapter connected
I may actually lose my mind over this beautiful machine. I've been trying to get it working for ages now. Found it in a charity shop in Sweden, came completely boxed, even the polystyrene packaging is barely damaged, this thing has clearly been looked after.
Quick backstory: booted it up when I first got it, worked fine, but there was no hard drive fitted at all when I went to install the OS. Opened it up and confirmed it, genuinely nothing there, previous owner must have pulled it at some point.
Bought an IDE to SATA adapter for an SSD, tried it, only got a grey screen and nothing further. Then bought the exact same adapter as someone in a video who has the identical model working. Same result.
The CD drive boots and works completely fine on its own when the adapter is unplugged. But the moment the adapter is connected to the IDE cable, even with no SSD attached to it at all, everything stops. No startup chime, just a grey screen. Holding Option or C does nothing. Holding the mouse button to force-eject the disc doesn't work either.
The adapter's jumper is set to Master.
I've attached some pictures of the drive and adapter setup, plus a bonus photo of a lovely G5 while I'm at it.
Genuinely stumped since someone else has the exact same hardware combination working fine. Any ideas what could cause a bare adapter, with nothing even plugged into it, to hang the whole machine like this?