My son had purchased a microwave and grilling oven for me at Christmas. Since using it has thrown a spark twice while boiling water to make a cup of tea. The cup was plain white with no design. I contacted the store (Walmart) who said that there was nothing they could do as it was a promotional item they got only at Christmas. I contacted the phone number on the back of the microwave and spoke with someone there. They told me to do a factory reset on the oven and then use it to see if it sparked. If it did I could bring it to Walmart with the... read full review »