Poorly LP12

My Linn Sondek can barely turn the platter. The motor has very little torque. They are two phase 12v as far as I know. My guess is that one channel has failed on the Valhalla board or the motor itself. The former is quite an expensive repair. It is one that failed once before, not long after I bought it in 1986. Back then, it was covered by the guarantee.
Here it is with the platter removed while I check the belt.
Posted from a mobile.

How do I fix this?

5°C, heavy non-stop rain.

Repair: my phone line is often very poor, the crackle & hiss is so loud that I can’t hear what people are saying and it often cuts off my ADSL internet connection. Okay, but it costs £99 to get a British Telecom engineer out and they may decide that it’s an internal fault and not do any repair.

So, now on a very wet Sunday afternoon, I could replace the internet wiring run from the BT box. It’s an intermittent fault, and what do you know- it’s clear right now.