Troubleshooting old laser...

[bill.french]

We've been running our laser for years, now. The power output was getting really low. I assumed the tube has reached the end of its life, and got a replacement on ebay, but am having a similar problem. In my mind, that says "well, it must be the power supply!" -- but i've heard so many stories about getting bad tubes on ebay, that i'm not sure.

I've been having trouble finding any kind of troubleshooting guide to help figure out if it's the tube or power supply. Here's where I am:
1. The tube does fire, and will cut, it just takes many many passes
2. I am seeing steady 16ma on the amp meter when the tube is running
3. Lens is clear

It seems to me that if the laser is firing, and running a constant 16ma, then the issue is not the power supply? Thoughts?

[sshwarts]

If I were me , I'd examine the mirrors carefully to see if they've degraded. I'd also triple check the alignment all the way through. An awful lot of power is lost along the optical path. I'd also redo a ramp test to check the focus.

Scott

[bill.french]

Mirrors look shiny and not cracked, lens is clear... not sure if there's something else to check? Our alignment is "ok", could be better, but all the light is getting into the head.

What i'm really looking for is some tips, tricks, steps, etc., for troubleshooting tube vs. power supply issues.