Eurorack case grounding issues

Hello! I got a second hand ALM 52hp 6U case and I am having some trouble with ground loops.

Certain modules are producing a lot of noise. My Music Thing Modular Spring Reverb MKii is giving non-stop buzzing when connected to the spring tank. My Befaco AC/DC is also giving a constant digital noise, even when all audio levels are set to zero.

In both cases, if I physically touch certain parts (e.g., the laptop it is connected to or the RCA outputs of the spring tank), the noise 90% goes away. This makes me think that the issue is with the case itself.

I have tried different power supplies but the problem persists. Any advice on how I can diagnose the problem?