Replacing stepper drivers on soldered MB

Because of the awful noise my new built 3D printer makes I decided to change the stepper drivers. The only issue is that they are soldered directly to the motherboard.

I have a Rambo 1.2g (=the big one) and basically have two options out of which right now only one seems viable to me. And I did not find much info on how to do it, so I would appreciate any advice or directing to place where I could find it.

1) I could replace only the drivers, but I dont think it is feasible to solder them back in without any damage, as the pins are not visible on the other side of the board.


2) I could just "steal" the information and energy input they need from the motherboard itself

It has broken out pins for the enable, direction and steps. It also has 3 x 5 pins for external motors, but I did not find out how do they work, what do they exactly do, and yet I want to replace drivers for all motors.
From my understanding I need the steps, direction and enable pins along with 5V logic circuit supply and 12-24 motor supply.
Could anyone please help me with info on where should I be looking for the pins for both power supplies?

Most driver chips aren't pin-to-pin compatible. That's done with a proprietary pololu-pincompatible driver-PCB.
AFAIK the drivers have an inbuild 5V regulator, so you'd only need 12-24V ( or even more ) and the 3 control pins for external drivers.

As someone who has replaced thousands of surface mount microchips before using only a soldering Iron. Want to tell you this is a venturous task that you a undertaking.

Want to warn you before you start, this is only for those Electronically minded individuals who are true soldering specialist.

I will tell you some clues of how I replaced Surface mount IC chips without special equipment.

NOTE: before you start locate pin one note it's position you will need to make sure the the pins match.
TOOLS REQUIRED
Magnifying Glass
Dull Safety Razor
Needle Point Soldering Tip (Or the smallest you can find)
Kester 0.022in solder

Most important item needed a needle point soldering tip. (I would Watch you-tube videos to see how they do it And even thru the disasters some really show you how to successfully do the job.
I used a dull safety razor blade and cut off all the chip leads carefully as not to cut the circuit board traces. (I reiterate a DULL safety razor blade)
Place the razor blade across the pins to be cut press lightly straight down you can feel the pins cut very easily. (Do Not Rock or you will cut the board traces)
(Now you can use a leister hot air surface mount soldering/de-soldering tool, I find it de-solders every chip around it so any movement of the board can dislocate those surface mount components.)
Then I used a soldering Iron to gently wipe the cut pins from the trace pads. Making sure to all pins are removed.
Using the smallest solder you can find mine is Kester 0.022in solder I pre-solder all traces that the chip will need.
(Just a little so you can see the trace is covered with a small arc. )

Using a magnifying glass place the chip so that all pins cover there single trace, without any overlap.
Starting at the number 1 pin identifier corner (without using any more solder) tack only pin one.
Moving diagonally across the chip align pins to correct position and tack only one pin.

Under the magnifying glass verify that all chip pins only cover their trace. once verified you can solder the rest of the pins in this manner.
Using a solder iron wiped clean with a moist sponge lightly touch every pin until it is tacked about 2 sec.
(DO NOT PRESS HARD OR YOU WILL BEND THE PINS CAUSING THEM TO SHORT TO THE ADJACENT TRACE)
When you have successfully solder all pins Under the magnifying glass verify that all chip pins only cover their trace and are soldered.

I repaired and calibrated speedometer clusters for a major car manufacture, we had a leister hot air surface mount soldering/de-soldering tool.
The chips were so small the the tool would blow them everywhere Made a bigger mess than it ever fixed, it de-solders every chip around it so any movement of the board would dislocate them.

Your local Tech College will have those who are most qualified to replace surface mount chips, and take donations for there services.

---

Computer Programmer / Electronics Technician

Thanks for the elaborate answer. I was doubting going for the solder out and then back in option and now it is clear that I should not do that. Also the new (different) driver is probably not gonna have the same pin layout as the old one, right?

I thought about going around them and just disconnecting them and stealing the signal that goes into them. I am not sure though how exactly the drivers work in regard of the power (meaning if I should connect the power somewhere from board or just steal it directly from the supply and if I should take it from the board what are the names of the pins I should be looking for.