Guys
Thanks for your responses, Saab, yes the hub is powered by the port, it has a small blue light on to indicate power, I don't notice this flickering when it disconnects but I'll observe it better. Thing is I have had the hub for 3 years, and have never had issues with it, it's only in the last 6 months or so it has started to happen. I wanted the issue sorted as I want to pass on my PC to someone else.
frost, thanks, I'll take the cover off and check out inside.
Thanks chaps
CC