I'm getting a "Gas pressure" fault on my plasma cutter (Hypertherm
Powermax 380). The PC monitors the gas (air in my case) pressure &
inhibits power to the torch if it falls below 40 psi.

I've:
- checked the pressure on the supply line - it never drops below 80 psi
- changed the filter on the PC

The PC has a built-in air regulator & gauge. It's set to 60 psi, as it
it is supposed to be. The pressure doesn't drop when the torch trigger
is pulled & gas flows.

If I set the PC's regulator to 80 psi it works. Sometimes. The owners
manual says to check the torch lead for pinched hose or obstructions.
This suggests that there is a pressure sensor in the torch & upping the
regulator satisfies it. But the parts diagram doesn't show one.

Any ideas? Before I start tearing it apart, which I'd really rather not do.

Thanks,
Bob