Any way to test a tube/power supply?

[aram]

We have a K40 upgraded with the lightobject DSP, other than that it is stock. The laser has been working fine (other than the basic issues these cheap lasers generally have), but suddenly seems to just not work. It was working fine, then sat for a few days without being used, and when turned back on does not fire at all. There is no glow in the tube, no reading on the amp meter, but the system turns on and everything else works. Just no laser.

Any ideas? Is there any way to test the tube and or power supply? I would assume it is one of those two. If anyone has any other thoughts, I'd be grateful to hear them.

Thanks,

Aram

[waltfl]

hi aram
did you push the red button on the laser power supply to check if this is working? it could be a loose or disconnected wire . it also could be that the fuse inside the power supply is bad if you open the housing of the powersupply you can see a glass fuse check it if it is still intact.
greetings
walt

We have a K40 upgraded with the lightobject DSP, other than that it is stock. The laser has been working fine (other than the basic issues these cheap lasers generally have), but suddenly seems to just not work. It was working fine, then sat for a few days without being used, and when turned back on does not fire at all. There is no glow in the tube, no reading on the amp meter, but the system turns on and everything else works. Just no laser.

Any ideas? Is there any way to test the tube and or power supply? I would assume it is one of those two. If anyone has any other thoughts, I'd be grateful to hear them.

Thanks,

Aram

[NickWL]

If you open the power supply to look at the fuse then BE CAREFUL - - there's the remnants of 23,000 volts that could be lurking inside the capacitors.
I don't know the insides of these PSUs well enough to advise any thing beyond being careful - but I advise that much in full measure!
Nick

[greg_gran]

You basically need to determine if you have high voltage or not. If you don't, it's the power supply. If you do, it's the tube. Measuring the high voltage requires a special high voltage probe like was typically used to measure the high voltage in vintage (CRT) televisions and monitors. You can pick them up on eBay pretty cheap if you look around. There are simpler ways using neon bulbs or even just holding a metal screwdriver with a nice long insulated handle near to the end of the anode wire and looking for an arc. Although I used to do this all the time 30+ years ago when I was repairing TV's I absolutely would NOT recommend any of these approaches today because of, well, certain liability issues...
Getting bit by 20kv is not a particularity enjoyable experience, I can vouch for that based upon first hand experience on several occasions.

I'd recommend you first look for physical signs of a failure of either the power supply or the laser tube. Check the fuse in the power supply as already mentioned. Trying to determine the presence of the high voltage should be your last resort.