Needed help with repairing HeNe Laser system

[LesWright]

For a quick and dirty test of the tube, disconnect it from the PSU, and hook it up to a piezo multi-spark cooker igniter similar to the one in the picture at the end of this post.
These generate about 10-15kV at current low enough not to damage the tube, but high enough that it will flicker and Lase (albeit at very low power, microwatts per pulse).
If the tube is good then its worth looking at the PSU.

[jonpaul]

These were popular in the 1970s..1990s.

Superseded by diode lasers.

The HeNe laser tubes  need many kV to start nd run at 500..3000 V DC perhaps 2...50 mA.

Thus the PSU is LETHAL and dangerous to test equipment.

Usually the HV transformer insulation or the HeNe tube fails after decades.

Not fixable.

Jon

[james_s]

These were popular in the 1970s..1990s.

Superseded by diode lasers.

The HeNe laser tubes  need many kV to start nd run at 500..3000 V DC perhaps 2...50 mA.

Thus the PSU is LETHAL and dangerous to test equipment.

Usually the HV transformer insulation or the HeNe tube fails after decades.

Not fixable.

Jon

HeNe lasers are still used and manufactured, it's true that diode lasers have replaced them in most applications but not all. The beam quality of a gas laser is far higher than that of any direct emission diode laser and HeNe operates one one of a few very specific and precise wavelengths which are not affected by the temperature of the tube.

I have never had a transformer fail, although I have had other failures in the power supplies which are mostly potted bricks, I have fixed quite a few of them by de-potting the affected area. If the tube has failed they can still be found. The power supplies can be dangerous but they are not likely to be lethal, the current is very low, typically 3-6mA depending on the tube.