98 Z71 - Keyless remotes quit working

I've had BOTH of my remotes stop working. Put new batteries in and it made no difference. I've tried every reprogram and re-learn solution I could find with no luck. Is there something in the truck that I can check? I'm starting to think that whatever receives the signal is bad. Any ideas? I know it's a minor problem, but it's one I would like to try and correct. Thanks.