Hi Nick,
Thanks for the reply, as it turns out thye ATL engineer turned up with a new ATL and it worked (3rd time lucky)
Got another dodgy one though, diagnosed as MOBO for 6300 after fitting new MOBO worked for about an hour then roboots every 5 mins!!!all cards detected on boot, seems normal, only alert is for votlage sensor detects something wrong with battery on MOBO (does this on both MOBOs), pinging works then lose ping and reboots.
any ideas?