The whole system seems to be wired up fundamentally wrongly somehow to me.
Are the slave cell connections fused as they should be with a 1A fast blow fuse in each lead?
If they are you should not have melted tracks or blown boards even if something is wrong.
If the connections from the cells to the slaves are off by even one cell then the whole thing will die.
Check again the connections from the cells to the slave boards.
Remind me again how many cells/slave boards you have?
The Master and Slave boards must not share the same ground.
The Master and lcd screen are best powered by an isolated 12v dc-dc converter. I have never had melted chips or blown boards.
I don't have any spare master/slave boards so do not wire that up until I get there.
Still waiting for the pics of the boards in situ with connections to the pack.
I need a series of detailed pics to have any hope of fxing it next week.
We are almost certain to need something from my workshop.
If I haven't got it with me then you are buggered as I am away on holiday for the following two weeks.
I'm rapidly comming round to the idea that you should bring the batteries and BMS here to me.
Please discuss this with them and bring the batteries and bms/master etc down to me if at all possible.
Peter