bobsterlobster
Joined 2 years ago
Karma
813
Submissions
42
Member since
Jun 30
Recent submissions
Comment · 7 months ago
What a blast from the past. I still remember seeing it for the first time on my Socket A Athlon 1900+ pc.
Comment · 7 months ago
>Did you buy this board already broken?
Honestly I have no idea what this board has been through before getting to me. It had the PWM/Temp/RPM issue from the moment I got it. Maybe someone did break the chip. I'm gonna look up that diagram and try to see if the pin is connected to ground
Comment · 7 months ago
I see, I see. That's an impressive amount of digging you did. Thanks for that.
Think I could wire pin 88 to ground and basically fix it?
Even if I do get it fully fixed, I think my project could be useful for motherboards that have thermal probes but no PWM.
Real talk though, I'd love to see this MSI board fully operational.
Comment · 7 months ago
Will do. Might be worth to look into it a little deeper.
Comment · 7 months ago
There's only one page for my board: https://www.msi.com/Motherboard/970-GAMING/support
And I've tried a couple of versions available there. I was even able to find some beta/unreleased bioses that I've also tested. Unfortunately, none of them enable fan control or fix temp & fan speed monitoring.
Comment · 7 months ago
Your hunch is correct, I did not test the PS/2, serial or parallel ports, and I'm only using USB.
Comment · 7 months ago
If windows crashes, then the audio generation crashes, so the fan will start to operate without PWM. Should default to 100%. At least that's how the PWM fans I have behave when the PWM signal suddenly disappears.
Comment · 7 months ago
Interesting idea, I'll look into it.
Comment · 7 months ago
I am not controlling a single fan though.
It's wired to a fan hub, so the PWM signal is sent to all the fans in the system.
I also wrote a companion windows application that reads CPU temps using PawnIO or HWiNFO which follow a curve that the user sets, and it sends the proper duty cycle to the arduino.
It's not just a dumb fan controller that I could've bought off aliexpress.
Comment · 7 months ago
Not sure how LLMs failed me, please elaborate.
Also not sure how you found that model number, it's literally an F71878AD, here's proof: https://www.modders-inc.com/wp-content/uploads/image/2015/02... Taken from here: https://www.modders-inc.com/msi-970-gaming-mobo/2/
I can show you a HWiNFO screenshot of it not reading anything off the SuperIO except Chassis Intrusion: https://imgur.com/a/dYPETWz
The only way I can get a temperature reading is off the CPU probe directly, which I am already making use of. As the article covers in later parts, I'm using HWiNFO and/or PawnIO to do exactly what you say (reading off the CPU probe sensor) and feed it into a fan curve, which then sends the appropriate duty cycle to the arduino.
In the BIOS there's no temperature reading, no fan speed display, and no PWM control whatsoever.
So maybe MSI did wire up the SuperIO, I can't say for sure, but they definitely didn't wire up something, otherwise the BIOS could at least control the fans or see their RPM.
And I've also tried with multiple BIOS versions, so it can't be BIOS related.
Some people online had working sensors on their MSI 970 boards, some didn't, leading me to believe it must've been a defective batch where they forgot something.
Image of an MSI 970 Gaming bios where temp and fans work properly: https://forum-en.msi.com/index.php?attachments/msi_snapshot_...
Comment · 7 months ago
MSI shipped a genuinely good motherboard and forgot to wire one chip, so PWM doesn't work. Instead of tossing the board or living with the noise, I decided to make lemonade.
An Arduino Nano generates the 25kHz PWM signal, and a companion Windows application reads CPU temp and sends the duty cycle over serial. The Arduino firmware is open source (MIT).