Well the new Head unit arrived, so I took out the faulty CDR500 and thought I'd have a quick look inside, whilst it is out of the dash.
So the CDR500 doesn't work to well with kids plastic toys stuck inside it, to be precise a small kids plastic ruler, obviously fed in at some point, to the delight of a small child that finds the hole in the dash eating his offerings noth.
Anyhow obstruction removed and hey presto the CDR500 works fine so...
Do I install the nice new Sony CDR DAB6650, with wiring harness to use the steering wheel controls and a snazzy remote control OR
Do I go back to the CDR500, with the steering wheel controls and the dash display ?
If I had known how easy it was to remove the head unit, I would have checked before ordering a new one.. oh well you live and learn.
MattP