3.5-inch USB hardware monitor screen not showing CPU temperature and frequency (0°C / NaN)

[Mircxulava]

Title: 3.5-inch USB hardware monitor screen not showing CPU temperature and frequency (shows 0°C / NaN)

Hi everyone,

I’m having an issue with a 3.5-inch secondary hardware monitor screen connected via USB. The application runs fine, and it successfully detects my CPU (AMD Ryzen 5 7500F) and GPU (AMD Radeon RX 6600) for general load percentages, RAM usage, and network stats.

However, the CPU temperature and frequency (GHz) always show as 0°C and NaN (or don't display at all).

Here is what I have already tried:

Ran the application as Administrator.

Disabled Memory Integrity (Core Isolation) in Windows Security.

Checked standalone LibreHardwareMonitor, which also struggles to pull specific sensor data for this AM5 platform.

It seems like an issue with accessing lower-level sensor data or a compatibility problem with the Ryzen 5 7500F / B650 motherboard sensors.

Has anyone encountered this issue with these small USB monitor screens? Any suggestions on how to fix sensor access for AMD Ryzen processors?

Thanks in advance!

[c0ldJS]

There are quite a few possibilities. The most common one is when Windows users have Python set as their polling method.

Windows users also need to be mindful of running the LHM .dll with an exclusion, though you should have seen a particular error dialog if this was the scenario at play (and only if you're on Windows).

Select antivirus and threat packages deem certain tools used in monitoring as vulnerabilities, and it can lead to goofy results. WinRing0 would be one example; inpoutx64 is another (which is currently causing headaches for gamers). In a lot of cases, upstream fixes are needed. Ideally, a safe_r_ kernel level bridge gets released that can replace the Old Guard but this hasn't happened.

My monitored box uses a B650-based motherboard (the retired version of the ProArt) and it's supplying full metrics.

[Mircxulava]

Thanks for the suggestion! I tried the things you mentioned (checking Defender and updating the LHM files), but unfortunately, it still didn't work.

However, I managed to fix it by using PawnIO as a low-level driver, and now it's finally pulling the correct temperature and frequency data for my Ryzen 5 7500F!

Just in case anyone runs into the same issue, you can find/install this driver alongside the app's installer. Thanks again for pointing me in the right direction!

https://pawnio.eu/

PawnIO_setup'.zip

[mathoudebine]

Hey, nice to know you found the issue! Did you install System Monitor using the windows installer? Because there should be a checkbox to install PawnIO during the process, and it is checked by default so wondering if you unchecked it for any reason

[Mircxulava]

Hey! I might have just missed it during the installation process, or maybe it got skipped. Either way, finding and installing it separately solved the problem right away. Thanks for the help!