cletis234 Hi, did you contact the support of Gratkit Team?
You can point out this then they should send you the replacement🙂
Another part, you may need to check other part is good or not.
"Sparks" sometimes means one part of the device under a short circuit.
Do a quick check may find out the reason.
For the 70C, you can refer to the FAQ then adjust the thermistor will fix it can't reach to 70C.