Tiny Tach Autopsy

[saskavid 47]

So most of us here have been using or had a tiny tach and have eventually seen the day where it succumed to the 5 year life expectancy and quit working....rather than just buy a new one I decided to do an exploratory crack open of mine before permanently abandoning it. Breaking it open did mangle the case a bit . This one was only glued along the bottom edge of the rectangular box. If they are all glued in the same manner then damage getting them open can be minimized only prying on the bottom edge. Once it was open, the only visual I got of the internals was a 3 volt lithium cell partially visible under a thin skin of some sort of rubbery injected foam stuff. The cell itself is attached to the power leads via a couple of small spot welds. Managed to pry the cell from its foam lair with some screwdriver prying on the leads. The cell was a 2325 designated. Closest I could come up with was a 2025 at a cost of 45 cents. Smaller diameter but identical/required thickness. Dabbed a bit of dialectric grease on the leads and installed the battery. powered up and all functions seemed normal. Got some gel form krazy glue and put a drop only on the 4 corners of the housing. Squeezed everything back together with 4 rubber tipped spring clamps and let the glue dry. Reinstalled it the next day and all functions are operational as original. Be interesting to see how long the fix works with the slightly smaller battery but at $.45 out of pocket and time it is worth a try and it works. 

[Allen Sutphin 705]

Yes it can be done. I used a dremel tool and cut the case in half.

[efil 01 74]

with a cylindre saw, i made a hole over battery location, changed battery and closed again with some tape.

then to keep good pression on the bottom, i scewed the tiny on panel with an aluminium plate;

15 YEAR old, and tiny start a new life