DIYbanter - How would I know if my HeNe laser tube is at end of life?

"LarryD" writes:

wrote:
How low would the power rating have to be on a 1mW 633nm HeNe laser
tube before it is considered end of life?
Sam, I need your help again :)

Try checking the high voltage with a CRT voltage checker. If the HV is
there, the tube is probably bad. I've repaired a number of HeNe lasers
through the years. 90% of the dead lasers were dead tubes.

I think the question didn't have to do with a tube that was dead, but one
that was weak.

A tube rated 1 mW is considered end-of-life when its power drops below 1 mW
at the spec'd operating current with proper mirror alignment.

In other words, the power rating is the minimum output power within the
tube's spec'd lifetime.

However, mirror alignment is often an the cause for low power and
that can be corrected.

(But if this was a tube from a Laserdisc player with an output of 0.8 mW.
I would expect that alone not to result in the player failing to operate
correctly.)

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