Cheers for the reply.
Found the problem was the small PCB between the fan connector and fan lead had a damaged track which was the yellow wire for controlling fan speed.
Repaired track and now working as should.
I think the problem with the condition of mine is if your a Business to Business customer there was no warranty offered on these.
Ergo the worst condition get sent to business custards.
2 of the units have about 10% device hardware errors and i am in the process of stripping, cleaning and re-thermal pasting them so fingers crossed.