My refrigerator is just over a month old, the light went out and I replaced the bulb. Didn't work. Any ideas on what is happening? Thanks.

I have a Kenmore dryer. I moved into an apartment a year ago and they changed my dryer from a 3 prong to a 4 prong power cord to match their dryer outlet. I just bought a 1972 home and of course it has a 3 prong outlet. I was tired and did sometehing stupid - I wanted to make sure the 3 prong cord I had would fit into the 220 outlet without turning off the breaker (yes I know I was lucky). The connections touched and popped (hit the wood baseboard and made a black mark). Although the brass looking connections on the power cord looked like they were a bit melted, I went ahead and hooked the cord to the dryer and tried it out. The dryer wasn't heating. I suspected that I fried the cord so I bought a new one and put it on, but the dryer still isn't heating. Could I have done something to the 220 outlet or the breaker? The dryer runs fine except for not heating. THANKS in advance for your help.