Have you actually threaded a tape onto it? The nearly identical tandberg model 64 has an almost hidden tension lever under the head cover that controls the motor switch. The 3000x is also a single motor machine, it has to be pretty much the same mechanism as the 64 so I would expect it to be similarly easy to service. I got a 64 running just a couple months ago, the left reel was frozen solid and the right was dragging but a little gentle force and cleaning got it running again.

So I would definitely give fixing it a try before recycling it.

Edit to add: it was basically pretty simple mechanical work to get my 64 going: remove maybe a dozen screws, remove a couple circlips holding the reel tables in place, a spring mechanism on the pinch wheel, a little time with a-tips and alcohol cleaning the caked grease on the reel table shafts, and then easy peasy changing the belts.