So let's start off by saying that I am a beginner and have basic knowledge of circuits.
So I was trying to 'fix' my thermal printer and now the stepper doesn't move.
I thought it might be a power issue and added a 16v 1000uf cap... to the 'input power'. the input power was 7v.
So I'm pretty sure I destroyed something, as I also inversed the cap... as nothing seemed to be happening (which was very dumb).
So I have 2 thermal printers and they seem to use the same chips and design and compared them.
The driver motor chip is 'A3906' Allegero (
datasheet)
The working one vs the not working one.
The 2 CP (charge pump) caps on the working one show 7v when clicking feed. The broken one does not. (0v)
The input signals voltage goes up on both when clicking 'feed'. and the broken one does print, except I have to pull the paper manually (as the servo doesn't do it).
I did remove the servo and test it independently and it works.
So my two thoughts are that either the capacitors are dead (which i kind of doubt) or the chip is dead.
Is this correct? Also is there an alternative to this chip?
Or I'll try to order it from aliexpress and perhaps painstakingly remove it and put a new one on. Also any tips for removing it as it has a soldered on pad (pad is a little dot on the back). I'm thinking of getting a hot air station, as I don't think it will work with a soldering iron.