Off odor on reconstituted starter

I dehydrated a starter for long term storage. I reconstituted it and that went OK, however, I put it in my container and left it in micro with just light on for proofing. It is active but has a very off odor. Not the pleasant sourdough that I have worked with in the past. The dehydrated starter is 2 years old but it did come back...wondering if the off odor is due to the heat emitted by light bulb in micro hastened the growth of a bad bacteria. I am going to feed again and let it sit out at room temp, which is probably 65F...if it still smells bad I guess I will have to build a new starter. Thoughts?