BAKU BK-601D heat gun failure

[ruky23]

hello all
me new to ur world, i come in peace, please forgive silly mistakes..
My crappie chinese made BAKU BK-601D bought online has given up on its heat gun abilities all of a sudden.
The fan works, the magnetic sensors on the handle work fine but just cold air(only fan) the element seemd not to be heating up anymore.
So, i just did a rework job on an old amd r9 and dice too! so it was working fine sand then the other day i fired it up and only cold air, visibly no "hot fiery look" around the rim of the gun.
Any idea what's wrong with this? i took apart the gun and inspected it for any discoloration, burning and so on but nothing.

Any help appreciated before i have to invest in another rework station, many many thunks!!