The Samsung SMH7175 Oven has some known problems that occur often. Here are some easy to do solutions for the problems or error codes your Samsung might be giving you.
The microwave power turns off unexpectedly, possibly due to a power outage or other electrical issue.
The microwave display is operational, but the appliance does not power on, which could be due to the door being open or a power supply issue.
There may be packing material or other objects interfering with the door seal, or the door might be damaged.