I recently bought a Type Y6142 battery and it's not charging, batterymon reports all capacities(design, maximum and current) as 0. The seller told me it's a stock one many years ago and it might be locked something.

When I press the test button on the battery no lights come on but if I press for more than 3 seconds, the 1st, 3nd and fifth lights will blink on and off. I understand the battery is probably bad but my question is what's the exact meaning of the light pattern? is it faulty cell? or it's bad circuit board inside the battery?

I am asking this question because I have a spare battery (same model) that is at the end of its life span. If it's just a bad circuit board problem, I might be able to fix it by salvaging the circuit board and solder it into the new one.