Looking at the picture, and make sure there is a working fan on the argon tube , do the following in sequence That tube needs at least 250 CFM of air across the fins at all times.
This is a educated guess, assuming there are no hidden controls, teh psu works, and the blower is still mounted on the laser. Proceed at own risk.
initial state
all switches off
turn on fan
turn on 3V,wait sixty seconds for warm up, cathode in argon tube should glow
turn on "tube"
usually on a nec its
blink, blink, blink, light. make sure something blocks the beam and protect your eyes. tube may light at that point, as NEC starters are automatic and in the head. If more then 8-9 amps after about 2 seconds, shut down right now by turning off "tube" NECs die fast (as in seconds) from overcurrent.
If it runs, has cooling, and its less then 8 amps, leave it run a few minutes
SHUTDOWN SEQUENCE.
Turn off "tube"
wait 60 seconds to prevent shock to cathode glass to metal seals
Shut off "3V"
wait 30 more seconds
turn off "FAN"
remember, dang, do not look in laser with remaining eye!.
The round plastic 9 pin connector is a amphenol CPC , aka circular plastic connector, available from DIGIKEY in the states looks like a standard sex 9 pin series one CPC, you need to order pins and a shell when you order the connector body You'd need a flanged receptical to mate to the one your holding up in the picture,
Steve Roberts