Melted cable at Einsy end
Does anyone here know the size of the screw terminal?
I have had the same issue as Neil. My other wires needing to be locked with screw terminal are fine except for the bed heater. I am 99.9 % sure I tightened the screw terminal but I wouldn't be in this situation if I had been 100% sure.
Additionally, I am replacing both positive and negative with longer cables. My MK3S came with around 16" and I believe it's not long enough.
I would also recommend everyone to check Prusa "quality crimps" as they not have been "crimped properly". Not blaming their crimping capability but 100% perfect crimping at all times isn't just possible.
This image attached is the crimping from the negative terminal. I am no crimping expert but I am sure, I am not supposed to see copper strands
I will say you are the first person to post in this topic in almost two years, so it can't be that common.
I do really like the suggestion of touching the heat bed terminals after running for an hour or so every few months.
If they are hot enough to burn you - you have a resistance issue developing. And a blister.