I have attached a pic of my tach that is not working. (sat for 37 years). I have read all the posts re: troubleshooting and have followed all instructions. Resistors all read within specs. All soldered terminals check ok. The blue capacitor, (at left of pic) apparently, is often the culprit. It’s the first time I have checked a capacitor, but my DVM has the capability to do so, but I get no uf reading at all. If I try straight resistance, I get no resistance at all and it shows complete continuity.
I was unable to get a close enough shot, but I can only make out “64V” and a “2.5”, but I can not make out any uf value markings?
I do not know what the round (grey/black marked) component is to the right of the transistor?
Does anyone know/recognize the blue capacitor and know what I would want to order to replace it. I am good at soldering, so if that is the problem, I can easily fix the tach if I know what to buy. If that is not the problem, then I will send it to someone!
The two input white wires and the green wire all have the proper voltages and the circuits are wired correctly. It is very clean, internally, and the needle is free without any corrosion, etc.