I'm building my first PC and have run into several installation problems. The liquid cooler is now installed and working, but the four fans in my SAMA S40 case won't spin. I was told the case-fan hub needs to connect to a SATA power cable from my Raidmax 850W non-modular power supply. However, I can't find a SATA power connector anywhere—only a cable labeled PWM. The motherboard is a B850M Eagle Wi-Fi 6E. What should I connect, and where can I find the correct power cable for the hub?
2 Answers
The liquid cooler and the case-fan hub are separate circuits here. The cooler uses its own PWM and ARGB connections, so its working properly doesn’t prove that the case-fan hub is powered. Check the hub itself for another connector besides the PWM lead—usually a wider SATA power plug or sometimes a motherboard-style power connector. Follow that cable back through the case and connect it to a matching SATA power plug from the PSU. If the hub has no power connector at all, inspect the case’s included accessories or fan-hub documentation, because the hub may be missing a cable or may need to be replaced. Until then, you can run the fans individually from the motherboard’s SYS_FAN headers, using a powered splitter if you need more headers.
The PWM lead from the fan hub is only for sending the fan-speed signal to the motherboard; it usually isn’t the hub’s main power connection. Look behind the motherboard tray and near the drive bays for a wide, flat SATA power plug attached to one of the permanent cable bundles from the non-modular PSU. That is the connector the hub would use if it requires SATA power. Don’t use a random adapter unless you’ve confirmed the pinout is compatible with the PSU. As a test, connect a case fan directly to a SYS_FAN or CHA_FAN header. If it spins, the fan itself is fine and the hub is simply missing its power connection.
I bought the PSU used and it didn’t include a manual. I connected one of the case fans directly to SYS_FAN and it spun, so the fans work. It looks like the hub is the part that isn’t receiving power. What should I try next?
The cooler is already connected and working; the problem is only with the four fans built into the case. I’ll inspect the hub for a separate power lead and keep testing the fans directly from the motherboard headers.