The Suprima manual is wrong here
if you have 220-240v dc on the solenoid from the pcb, both the pcb and solenoid are OK, if you have 0ver 300v dc on the solenoid, the solenoid is open circuit.
The solenoids have a resistance of 2k8 and 1k4 ohms
From this you should be able to deduce whether the pcb is working or not, and leaves the mechanics of the gas valve as the culprit.
geoff@cet
February 2008