toasty pcb? or the liner is in such poor condition the wire is having trouble getting up there.
easy way to check liner, watch the pinch rollers to see if the wire slips as the pinch rollers turn. could be the pinch rollers require more pressure, or cleaning but its often signs of a new liner is required. the other way to check the liner is to free the pinch rollers and pull the wire from the tip end out, if it moves free thats good, if it requires a fair bit of effort then the liner is damaged, one last thing to check, is on the wire reel there should be a break this is to stop the wire from turning after the wire feed stops drawing wire, its nothing more than a friction brake, controlled by tightening a nut. just check the wire reel is free to rotate, but has some friction on it. If its none of those it could be the PCB that controls the wire feed or more likely the rehostat. open the machine up and check for damage, black or brown bits on the PCB