Update time! Back in 2006 I bought a Portamig and it's been fabulous for welding Renaults. But it's a MIG not a TIG.
The Syncrowave problem turned out to be the hall effect thing that measures current in the the main output lead so the current can be fine tuned. Les from Tec-Arc sorted me out with one of those and also a bit for the foot pedal which also works now.
I don't use the Syncrowave as Steve from Weldequip lent me a Inverter Fusion 200HF. Was struggling to learn TIG with the Syncrowave but it clicked with the IFL. Haven't tried the Syncrowave since to see if I can use it after TIG Paul taught me how to TIG.
Going to need to weld aluminium soon. Will have to check the Syncrowave still boots up.