hamilton led with alarm in trouble

[birox]

Hallo, from a day to another, an Hamilton led with alarm switch off. Closed in a box, day before run,day after don't. The battery have 1,56 volts each,then naturally isn't a battery low problem. Will be Frontier module,seems clean and oxidation-free.
Someone have any idea??
Thanks a lot.....

[retroleds]

Short of pulling the module apart...some ideas.
1. Be sure battery contacts are clean.
2. While gently pushing in, rotate each of the two spring which stick out of back of module several times. Basically you are trying to get the end of the spring to clean a spot on the aluminum contact area it touches, without having to open things up.
3. And you understand the back must be on for it to operate? No offense intended.

[birox]

Tanks for this suggest... I've previously cleaned softly the battery contact on main board with 8000 sandpaper. In this module there is conductive rubber from the external gold contact on module case and the mainboard module contact. I think will be there the problem. With multimeter this rubber seems so low conductive...