I use my Tacwise 191EL quite a bit for making bee equipment, so I was a little distressed when it stopped working. After doing the easy “check the fuse” type stuff I decided that since it was out of guarantee anyhow there was little to lose by taking it apart.
Once in pieces, the problem was pretty obvious. The switch (the upper one in this photo) had failed. The slider had snapped off and the mechanism wasn’t sliding properly so it was never triggering the gun to fire. I’m not entirely sure why the slider had failed. The trigger doesn’t actually press on that part at all, instead making contact with the end of the slider that is inside the switch (which is sprung, so it returns once the trigger is released). Missing the slider however means that the mechanism becomes unstable and tends to jam or even travel too far.
I tried a few bodges, but couldn’t get the switch to work reliably. In the end I just decided to replace the switch. I wasn’t able to find a direct replacement, so in the end I made up a small carrier from an offcut of aluminium plate and added a momentary button that would be operated by the trigger.
The range of movement of the trigger is smaller as a result, but at least the gun works once again and I don’t have to splash out on a new one.