not working right.

[justinsanders]

just got my new laser off ebay and the button doesnt wanna work all the time. then when i does sometimes its not very bright. then i'll wait a minute and it will either work perfectly or not at all. whats wrong? thanks

 

[MarioMaster]

i'm sure most of the other users will issue their standard "don't buy lasers from ebay" speech, so i'll get to the point that your laser is probably poor quality and either not maintaining proper contact with the batteries and casing which it is causing the differences in brightness.

the crystal may also be slightly out of alignment

 

[danq]

The first thing to check, as said above, is whether there's good electrical connection.

I had a cheap 10mw that was intermittently working when new. When I took it apart, I found that there was a very poor pathway from the positive battery end to the laser diode. It had to go through the following:
- battery to switch (nickle to tin/lead)
- switch contacts (unknown)
- switch to encap (unknown)
- endcap to main body (aluminum to aluminum)
- main body to front body (aluminum to aluminum)
- front body to laser module (aluminum to brass)
- module case to laser module (brass to brass)

The main culprits in my case were the last two, plus the switch; but as you can see there are many possibilities. The Al/Al and Al/brass are the worst, potentially.

one added note: when selecting a cheap laser, it might be better to choose one with a switch on the body rather than on the endcap. The body switches are usually actually on the circuit board so the electrical path is cleaner; and even cheap ones are likely higher quality than cheap endcap switches.

DanQ