EME-156 repair

[btr]

Hello everyone,

I'd like to apoligise in advance if I say something totally ignorant, I'm new to this forum and TBH also new to Amstrad CPC.
Few weeks I got my hands on a 6128 which needed some basic maintenance in order to get it working. After fixing a power switch and cleaning up the mainboard I was able to turn the machine on and successfully load some tape images.
After that I proceeded to floppy drive repair and that's where I got stuck. Here's what I did so far:

• Replaced rubber belt
• Cleaned and lubricated stepper motor screw and head rails
• Carefully rubbed the head with a cotton swab and some IP alcohol
• Cleaned track 0 sensor the same way

After that I was able to successfully read a disc for a brief moment. It was refusing to work sometimes, but usually power cycling the machine was enough to get it back to work (still weird though).
Then I formatted it with Discology and that's when my problems started. Apparently it tried to format tracks above 41, so for a moment, the head mechanism was banging against stepper screw mount. I suspect that the stepper got de-calibrated because of that.
I tried to align it with an oscilloscope, but I'm getting no signal from TP1/TP2, just a flat line.
I tried replacing a pressure pad, as the old one was pretty worn out and I hoped that disc surface was just getting too far from the head, but still nothing. I've also checked for dry solder joints and checked for severed PCB connections with a multimeter, but everything looks good: there seems to be a good connection between the head and the controller IC, same for test points.
At this point I'm out of ideas. I really hope the controller IC is fine and the head isn't damaged. Is there anything I could have missed in the process?