Khms155lss-3 Magatron is broken and i need to replace it.

The clicking sound would probably be a realy on the Circuit board. Do you have it set on Full power?? If it is set on a lower power setting the relays will open and close to try to regulate the cook power.

The keypad has a shorted membrane and must be replaced to fix the problem.

open *** and follow the cable which come from the back you will see an enclosure with fuse inside. Remove the fuse and replace with an other one with same specifications

Did you ever find a fix? Mine is doing the same thing!! Uggghhh!

good day,
hope this link below will solve your problem.

kitchen appliances

faulty keypad

take screws out of side then use flat butter knifes to hold the push pins out of the way so glass comes out then get to the handles

you will need the whole control panel, not to expensive

http://www.fixya.com/support/p105806-kitchenaid_khms155lss_1000_watts/manual-13684

I had the same problem with the same model of KitchenAid Microwave. KitchenAid customer service will act like they never heard of the problem, although if you google it, you will find that this is a very common problem. Ask to be transferred to the safety department. After more than 6 months of complaining and several repair attempts (they replaced control panel and switches), KitchenAid finally gave me a full refund. This is a serious safety defect for which they have no fix. The product needs to be recalled, and I am willing to testify that KitchenAid was criminally negligent when this product finally causes a house fire and possibly serious injury or death.