S12S controller - removal of solder from shunt, now motor does not run

[pn_day]

Hi all,
I've made a foolish blunder.

On measuring current to the S12S I discovered that I'd been allowing up to 32A due to getting a little exuberant with adding solder to the shunt. I therefore decided to remove a little solder using a soldering iron and solder sucker, and also decided to use it to teach my son the basics.

Unfortunately I'm obviously not very good at talking and soldering, and now the controller appears to work as normal according to the LCD3, but the motor does not turn (either with PAS or throttle). When using the throttle the display shows the throttle is being engaged (the 4 lines rotating around a square) but the wheel refuses to move.

I'm assuming I've either created a gap through excessive heat, or alternatively a solder bridge.

Anyone have any ideas of what I should check first? Is the first suspect the shunt itself?

Secondly what is the easiest way of removing the board? The end caps are easy, but I'm not sure whether to remove all screws from the heat sink down the side.

(Fortunately I had a spare S12P so the bike is running, just not quite as smoothly as before!)

On a somewhat related point, if I cannot fix the S12S is the S12SH a worthwhile investment, or should I just get another S12S?

Thanks in hope,
Phil

 

[Deleted member 4366]

You have to remove the screws in the side to get the pcb out. Mine was very difficult to slide so needed a lot of force, although yours might not.

It would be difficult to damage the controller by soldering in the area of the shunt, so I'd look elsewhere for the cause of your problem unless you've left one end of the shunt unsoldered to the pcb.

 

[pn_day]

Thanks d8veh.
I'll have a look this week.

I did end up getting a frame bag by the way - haven't done a long trip on the bike yet since then, but balance just going round the block is much better. I hardly notice the weight unless I have to lift the bike unlike having the battery on the rear rack.