Never got a chance to do a thing today

I have doubts about my stepper board being pucka (a mechatronics easy cnc 3 axis)...I'm of the opinion that this board is causing some missing steps - also two of the 3 Allegro A3977 ICs on it are in part duff (they don''t allow microstepping - therefore only full stepping ...so my resolution is not what I'd want), so therefore the lowish resolution & potential for steps going missing (the A3977 socket have poor contact with the IC pins), I feel is likely to be - in part significant. I have a rather out of proportion spindle (it's a beast for the size of the machine), so my stepper board needs to be up to driving it.....this I feel is likely to be my main problem area...steps going awol on the Z axis.

So I want to change my stepper board first - I have a TB6560 board lying around...but it's an ordeal to wire it into my setup as I have a CNC-USB board that I need to connect up to the TB6560 ....the CNC-USB has 10 way ribbon outputs...so got to do a bit of soldering. (I'm aware of the number of folks having missing steps issues with TB6560 variants too....but such a board is normally fed from a paralell port, whereas my CNC-USB board will be driving it....with a very short cable (which I'm hoping will avoid the need to buffer the signal - which is the normal workaround for when TB6560s miss steps.)