Hi there, Apple does not offer data recovery on a Time Capsule. One possible way you can give it a shot is to remove the HDD and connect it to a functional computer for data recovery. But you should bear in mind the HDD removal violates the Time Capsule warranty which prevents you from returning the broken one for a new one.
If the files stored in the Time Capsule matter much to you, you can try the risky method and use iBoysoft Data Recovery Software for the inaccessible files. Or, just send the Time Capsule to Apple for a replacement.
Finally, please back up anything important regularly since data loss always happens without a sign.