Above is the laser pointer with the
battery holder removed. I used a Dremel rotary tool with a
cutting wheel to cut completely around the case. I cut through
the case at the center of the small pushbutton switch; see below.
Above is the case with the battery
holder removed; I've also unsoldered a small spring that was attached
to the center tab on the PCB. You can see where I cut into the
through the center of the switch. Note how close the tiny PCB is
to the wall of the battery holder! There isn't much free space;
if you run the cutting wheel in too deep, you will destroy the PCB!
Above is the final hookup, showing the power cables I added so I can
apply 3 - 3.3VDC to turn on the laser. Note that the positive
lead is wired to the PCB and to the case! If you don't make this
connection, the laser won't light. I used a scalpel and small
file to clean off the rubber covering of the laser barrel so I could
solder directly to the barrel.
Note: I connected the positive lead to the barrel of the pointer
because this laser pointer wants the positive terminal of the battery
connected to the metal of the barrel. If your laser wants the
negative terminal of the batteries hooked to the barrel, you will need
to make a suitable change when you wire up your power leads.
As shown, the small switch is no longer functioning. If I apply
voltage to the two wires, I get laser light.