I recently bought a set with an RPI4, PSU, Ninja Coupe’ cover and a fan-shim.
After assembling and powering up the device, I had to check 3 times to make sure the fan-shim was working (I’m using it without the script) as it was really silent. Amazing.
Now, after two weeks, it started buzzing too loud so I was wondering what could be the cause.
I disassembled it 2 times: checked everything, used some canned air to eventually clean the dust, and carefully put it in place again, but to no avail.
I have actually discovered that the RPI4 has an issue with the external powered USB HUB I was previously using. The HUB power-backs the RPI with the +5V pin, preventing it to start properly.
I was wondering if this issue could be related to the noisy fan-shim (somehow “super-powered”) or could be something different. In this case, could someone suggest what to check ?
Thank you in advance.