Dreamcast Fan Noise

Hi. My Dreamcast fan seems to have developed a rattling noise which keeps coming and going every few seconds. I have a couple of 40mm Gelid fans and I tried hooking one of those up to 12v on the PSU to use one, but the system just kept resetting itself just like the fan RPM problem, meaning I had to just revert for now.

 

You can bypass the fan speed check.

https://assemblergames.com/threads/dreamcast-fan-replacement.57405/page-5

 

In the end I had just gone with the 10k resistor between 12v + tach and now the Dreamcast is working properly

But I'll keep that mod in mind should I ever want to use a fan that doesn't include tach.