All,
I'm trying to get a Varian Prostar 320 detector (an ebay acquisition) repaired. Everything is OK except I get a low light error when it calibrates. I figured it was probably in need of a new bulb, so I bought one ($500 ouch) and installed it, but then I got sporadically either a no light error or the same low light error. (If I pull the holder out, the bulb is definitely igniting, so not a bad bulb, and it goes back to low light with the original bulb.))

So...

1) Any tips on what it might be beyond the bulb? (I did air spray the flow cell windows, too, and tried a spare flow cell - no improvement.)

2) Does anyone have a service manual for this module? I have another 'parts module' that I could potentially swap parts from (it doesn't power on anyway), but some guidance would be nice.