- Check your owner’s manual to ensure that the power cord is grounded appropriately. It should be plugged into a 3-pronged electrical outlet. Also, make sure to check fuses and circuit breaker.
- Pour a cup of water into a glass measuring cup and place in microwave. The water is used for two reasons: 1) you should never run a microwave while it is empty; foods and liquids help absorb the microwave energy, and 2) it will help you feel temperature differences later on.
- Close the microwave door and microwave the water for 1 minute. Take note if the light comes on or not. Put your hand over the back ventilation opening and note if you feel air coming out. For R-21HT, R-21HV and R-21JV models, not whether or not the “ON” indicator comes on.
- After the 1 minute passes, pull the glass measuring cup out of the microwave and test the temperature of the water (careful, don’t burn yourself). Note if the water is hot or not.
If the light isn’t coming on, you feel no air coming out of the ventilation opening, and/or the water isn’t warm when you test it, you may want to contact Sharp authorized repair vendor. If your microwave is still under warranty, make sure to let the vendor know.
If what you’re seeing, however, is the timing rapidly counting down, the demonstration mode may be on. To reset/cancel this, simply unplug the microwave, wait 30 seconds, and then plug it back in.