HTC One M8 sim card not detected after replacing the battery.

Replaced the battery in my HTC One M8 and after the phone was put back together, it was telling me the sim card was not present even though it was. I triple checked all the connections. I'm pretty certain i was careful and did not damage anything. Having said that, in an event that I did and didn't realize it, any suggestions at what parts might be responsible that I should try to replace first? Thanks for any assistance.

Welcome to Android Central! Have you already tried removing the SIM, blowing out the SIM slot with a can of compressed air, and then reinserting it?