Remove the two screws to the plastic vent strip at the top of the unit. That exposes a metal cover (upper right) held in place by two more screws. (Found that removing the screw holding the key panel in place and moving that out of the way made for more work room) Remove the metal cover. The HV diode (visible) on one end is secured to the chassis by a screw. The other end is fitted to the HV capacitor. So unscrew one end and pull the HV diode off the capacitor. The replacement fits on like the old one came off. Very simple repair. But it would be safe to short the capacitor terminals to the chassis first. Noticed that it appeared the sparking was caused by the HV diode's outer casing being worn by the asbestos covered wire next to it and laying against it. I made sure the two were not touching, before putting the covers back on. Also, the problem started with an occasional spark when the MW started. It quickly deteriorated to a full, non-stop electrical sparking. You can hear it, smell it, and see it through the top vent. You don't need to remove unit to work on it.
We needed a phillips head screw driver to remove the single screw holding the light bulb cover in place. Removing the old bulbs was a little work, because they had come loose from the sockets. We unplugged the microwave, so we could grip the sockets with a tool. I think my husband used a needle nose plier for this. The new bulbs screwed in easily, and then we refastened the light bulb cover with the phillips head screw driver.
PartSelect website indicated replacing the high voltage power supply diode is the solution for "no heat" 99% of the time, but the diode was OK. There is more info at the website concerning the case of "loud buzzing and no heat" indicating the magnetron needs to be replaced. As an electrical engineer with knowledge of microwave components, this was also my best guess. However, getting to the magnetron is not the easiest job, but it's not impossible. You also have to be careful to bleed off any charge stored on the high voltage power supply capacitor. Luckily, I found my KitchenAid service manual tucked away inside the unit since I couldn't find it online.
I removed three philips head screws from side of door panel and unclipped to remove. Finding Parts Select was great! I had the right part in two days. Fit and color were perfect. Thanks much.
Rep knew exactly what I needed when I described where the part should go on my microwave - price great - shipping great - installed in seconds. Thank you!
Dropped the glass cooking tray and it broke in half
Looked up the Whirlpool Co. and ordered the part. It was quite simple. Arrived in 2 days and I simply placed it in the microware. It was very very easy!
Simply removed two screws to remove the old vent grille and replaced it with the new grille. I was also very pleased with the assistance I received from the service rep. I had ordered the wrong grille. I called the PartSelect help number and the rep walked me through the product return process, then found the correct part and ordered it. I had the replace 3 - 4 days later. The rep was very polite and patient during the whole process.