How can I repair my JVC DR-MH20 DVD & HDD Video Recorder?

I bought the above dvd & hdd video recorder a couple of years ago on e-bay and it's never quite been 100 %. I've had difficulty recording onto discs and sometimes I'd set it to record on the hard drive and come home to find it flashing and saying 'LOADING' so I'd switch it off at the wall and leave it off overnight, then switch it back on the next day and it would be ok - just needed to reset the time and date. It recently did it again and no matter how many times I turn it off and leave it overnight, it doesn't seem to make any difference; it keeps on flashing 'LOADING' all the time. Can someone tell me if this is a common fault that I can repair myself or do I need to take it to a repair shop and will it be worth it, or is it better to invest in a new one? I live in the St. Albans area if anyone knows of a repair shop close by. Many thanks.