Radio issue

I decided to upgrade my renault radio in my 2005 Clio1.2 recently and installed a Sony DSX-A40UI from Halfords. i followed the instructions to the letter and it worked perfectly. ASbout a week later it suddenly stopped working(it powers up but only beeps when I press any of the buttons) and the clock also vanished form the dashboard. The clock re-appeared two days later but the radio remains the same. I changed the radio fuse to a new one even though the old one appeared OK. All the other fuses are intact both in tyhe car and under the bonnet. Anybody have an ideas on whatsup??