Question Problem with fans on Linux/Windows 10 Dual Boot System ?

Apr 4, 2021
Linux/Windows 10 Dual Boot. Ongoing fan issues but after updating BIOS I received fan/chassis id errors and now motherboard fan is reading at 0 RPM ?

I purchased a refurbished Dell Inspiron 620 running Windows 10 in January and installed Manjaro Linux alongside of it as my main OS. The only issues that the PC has had have been concerning the fans.

The CPU temp would sit in the low to mid 30Cs under normal circumstances with PSU/case fan speed around 1200 RPM. If I went onto a website like Reddit, Youtube, Amazon, etc the temp would only climb to the low to mid 40Cs, but the fan speed would get all the way to 3-5k RPM. It would rev up and down constantly as I used the websites.

I purchased an Asus wifi adapter, so when I installed it I cleaned out the case as well. I took apart the PSU, fully cleaned it to the best of my ability using a forced air canister, and did the same for the motherboard, case, etc. Everything seemed fine; there wasn't a ton of dust. After that the fans seemed to improve only slightly but still revved and stayed on pretty high and loud.

Yesterday I needed to use a software that isn't available on Linux so I booted into Windows and decided to try looking at the BIOS and updating them. Before doing so I did the ePSA Dell Diagnostics and it notified me of two error codes:

  1. Error code 2000-0511 - Msg: Fan - The [System Fan] failed to respond properly
  2. Error code 2000-0415 - Msg: Cables - Check the following cables: Chassis ID
I did some quick googling on those but decided to try updating the BIOS first to see if it helped at all. I couldn't download the most recent BIOS since it isn't supported on this old of a computer. However, the BIOS that was installed was fairly old compared to the one I was able to get (2013 release).

After downloading and restarting the computer was whisper quiet and I thought the BIOS finally fixed the problem. Before proceeding to try to update it for Manjaro as well, I did the ePSA diagnostics again and it found the same problems. I decided to put it off and proceed to update the BIOS on Linux first.

When I went into to Linux I ran lm-sensors from the command line to see what it would tell me. My temps are now sitting in high 30Cs to low 40Cs and they climb no higher than the mid 50Cs when going on websites as before. The PSU/case fan doesn't seem to be kicking on as before and the temps aren't climbing anywhere near crit level. However, I'm a little concerned that my processor fan is reading at 473 RPM and my "Motherboard fan" at 0 RPM. I don't know what motherboard fan means. Is that the PSU/case fan?

I'm going to guess that this isn't normal... and I'm wondering what to do to troubleshoot this. Does the PSU fan need to be replaced? Is it fine to leave as is if temps aren't reaching high or critical levels? What caused the initial fan problems and why is the Motherboard fan not moving above 0 RPM now?


In general, control of the fans for cooling is done by the mobo by its BIOS, and does NOT depend on the OS. Your system will have three "groups" for fan control. The fan inside the PSU is NOT under control by the mobo, although it MAY have a way to report its speed to the mobo for display and to monitor it for failure. IF that fan's speed is controlled, that is done entirely within the PSU.

The mobo always has two cooling control systems. Each is guided by a temperature sensor for a component, and the automatic (default) system alters the speed of its fans to hold the measured temperature at a target. Most fans report their speed to their header. Although that info is NOT used for speed control, it is monitored for fan FAILURE. The CPU_FAN header controls the cooler on the CPU according to a temp sensor built into the CPU chip itself. The SYS_FAN header(s) control case ventilation fan(s) according to a temp sensor on the mobo. In your case, the error says that the SYS_FAN header on the mobo is not getting a fan speed signal from the fan plugged in there. That could be just a bad connection at the fan header, or the fan may actually have failed. You need to open the case, find the fans and exactly where each is plugged in, and then watch them carefully (especially the CPU and case vent fans) as they first start up. The NORMAL sequence is this: when you first turn on the system, all those fans should start up immediately at full speed for a few seconds. After a short time as the mobo completes its POST tasks the system gets temp readings and starts to use the automatic control algorithm. This causes most fans to slow down to what is required, Subsequently as workload (and heat generation) varies, the fan speed will change.

Watch your case ventilation fan particularly, since it is reporting trouble. If it is NOT turning, it may have failed. OR it may just have a bad connection as the header. UNplug it gently, then plug back in. Repeat a few times. This MAY "scrub" and oxidation off contacts and help. Check carefully that you have not disturbed any other connections. If the fan still does not work, it may have failed and require replacement. If the fan seems to ne operating normally and changing speeds, check again for the error message.