So far we have run a system test and a memory test on the diagnostics. Both gave error code 'RW09VH-8AP8JQ-XD7X7F-40EL03 MM1 for the system test and the same code again for the memory test but with 'Bottom slot one' rather than memory module 1 at the end. The HDD test passed. What would you suggest next? Thanks for your help!