Hi Jasper,
I know this is an old post, but I just picked up the same machine and was wondering if you would have any advice.
It didn’t include a power supply - I picked up a 15V DC supply, but the machine still doesn’t turn on. The power LED blinks for a moment though. I also tried using a 12V DC supply, and it runs for a moment when I hold down the power button, but then shuts off.
The playhead on mine was also jammed, but I was able to use the flywheel to coax it back into position. Thanks in advance for any useful info!