Lenco L-84 USB Turntable - faulty (Telford and Wrekin TF7)

I bought this a few years ago, hoping to digitise some of my LPs. It's very simple to operate, and is complete with mains adaptor and output via phone leads as shown. However, from the beginning it had a tendency to skip tracks. The only way I could solve the problem was by putting a light washer on the tone arm to add a little weight. Fearing this might damage my vinyl I gave up, and recently bought another deck. If you know about these things you could probably rectify the fault. I have the full manual, downloaded from the internet.
Drop me a message if this might be of interest to you.
ColinMud