Buzzing Noise coming from Instrument Cluster - 79 Mercedes 280E

I have a euro 79 280E. I had an issue with a loud electronic buzzing noise coming from inside the instrument cluster at higher speeds. Once I get to around 60mph+ the noise would come on and then stop when speed decreased (under 30mph).

I thought it was a spedo cable issue and had the cable replaced a few months ago - no issues for a while but the noise just came back. It’s not exactly the same sound as before but is a similar loud buzzing/vibrating noise coming from the cluster when I’m going at least 30 or so.

Any ideas on what this could be outside of the speedometer cable?