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Built a cheap DIY fan controller because my motherboard never had working PWM

himthe.dev

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Re: Built a cheap DIY fan controller because my motherboard never had working PWM

#41

Post by dv_dt »

MisterTea wrote: post #21
adrian_b wrote: post #16

Earlier quoted context omitted.

True, a very simple analog circuit would be enough. However the bane of analog circuits was that they age, so a control circuit that works perfectly today will drift and no longer work as intended after some years. The second problem is that analog circuits need adjustments to set them at the exact desired parameters. Adjustments can be done either by using an adjustable element in the circuit, e.g. an adjustable res…

You're over thinking it. If the application is very simple and needs to do one thing, an analog system works fine. Once you start needing sequencing, multiple adjustments, and maybe a little smarts then a CPU can get involved. I worked at a shop that had an old closed loop water-air chiller for a laser. The water temperature controller was a small PCB with an op-amp chip with some passives and the temperature was set…

My analog fan control comment was a bit tongue-in-cheek, but turning a knob on a potentiometer to adjust fan speed has some personal appeal - no digging around for a sw utility, no poking interfaces to see if the motherboard mfr bios exposed the control, of if it exposed it but doesn't actually hook the right plug, no adjusting to see if the right temp input is reading correctly. Fewer layers of things to go wrong can be so nice.

Re: Built a cheap DIY fan controller because my motherboard never had working PWM

#42

Post by rasz »

bobsterlobster wrote: post #29
rasz wrote: post #12

>This board has a Fintek F71878AD, a perfectly capable Super IO controller that can read temperatures, control fan PWM, and monitor fan speeds, but MSI just didn't connect it to the board. is not true. There is a diagram available for this mobo and U32 (F71889AD) is connected over LPC (modern serial ISA version). Its a full Super IO and it cant be _not connected_ as it also provides keyboard/mouse, serial and printer…

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 g…

>how LLMs failed me

I assumed LLM gave you or validate the idea one of the biggest mobo manufacturers on the planet didnt wire temp/fan control on their flagship Gaming board?

>not sure how you found that model number

manufacturer diagram of MSI MS-7693 rev 2.0 (970 Gaming) https://www.elvikom.pl/viewtopic.php?lang=en&t=54275&p=21060...

> it's literally an F71878AD

rev 2 specifies F71889AD but Im pretty sure all Fintek F71868/869/870/878/882/889 are more or less compatible https://docs.kernel.org/hwmon/f71882fg.html https://www.linuxquestions.org/questions/linux-hardware-18/f...

rev 4.0 and up do list F71878AD https://www.scribd.com/document/961738196/MS-7693-Rev4-2 https://html.scribdassets.com/5xds0sz8hsgb4iux/images/27-e6d... diagram has all the fans and temp stuff wired up.

Only one pin comes to mind that would break all temp sensors, fans and Voltage monitoring but not ps2/serial/lpt, that pin is 88 analog ground.

>HWiNFO screenshot of it not reading anything

HWiNFO has this "feature" that makes it hide sensors reporting maximum/minimum possible values. HWiNFO considers such readings sign of a missing/broken sensor. Broken analog ground pin on your motherboard would make all those sensors return bad value.

Video of someone running hwinfo successfully on 970 gaming rev 4.x (F71878AD) https://www.youtube.com/watch?v=Wq50OuGC1ys

Re: Built a cheap DIY fan controller because my motherboard never had working PWM

#43

Post by rasz »

toast0 wrote: post #33
rasz wrote: post #12

>This board has a Fintek F71878AD, a perfectly capable Super IO controller that can read temperatures, control fan PWM, and monitor fan speeds, but MSI just didn't connect it to the board. is not true. There is a diagram available for this mobo and U32 (F71889AD) is connected over LPC (modern serial ISA version). Its a full Super IO and it cant be _not connected_ as it also provides keyboard/mouse, serial and printer…

> Its a full Super IO and it cant be _not connected_ as it also provides keyboard/mouse, serial and printer ports. Maybe the ps/2 port and serial/parallel ports also don't work? Lots of people use USB for human inputs, and few people use serial/parallel ports, so I wouldn't expect OP to have tested those ports. They probably work on most boards, just like the PWM probably works on most boards. But his board seems to…

Bios would error out after not being able to initialize PS2 controller.

Re: Built a cheap DIY fan controller because my motherboard never had working PWM

#44

Post by bobsterlobster »

rasz wrote: post #42
bobsterlobster wrote: post #29

Earlier quoted context omitted.

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 g…

>how LLMs failed me I assumed LLM gave you or validate the idea one of the biggest mobo manufacturers on the planet didnt wire temp/fan control on their flagship Gaming board? >not sure how you found that model number manufacturer diagram of MSI MS-7693 rev 2.0 (970 Gaming) https://www.elvikom.pl/viewtopic.php?lang=en&t=54275&p=21060... > it's literally an F71878AD rev 2 specifies F71889AD but Im pretty sure all Fint…

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.

Re: Built a cheap DIY fan controller because my motherboard never had working PWM

#45

Post by rasz »

bobsterlobster wrote: post #44
rasz wrote: post #42

Earlier quoted context omitted.

>how LLMs failed me I assumed LLM gave you or validate the idea one of the biggest mobo manufacturers on the planet didnt wire temp/fan control on their flagship Gaming board? >not sure how you found that model number manufacturer diagram of MSI MS-7693 rev 2.0 (970 Gaming) https://www.elvikom.pl/viewtopic.php?lang=en&t=54275&p=21060... > it's literally an F71878AD rev 2 specifies F71889AD but Im pretty sure all Fint…

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.

> Think I could wire pin 88 to ground and basically fix it?

I think you could check if the pin is reliably connected to ground.

Did you buy this board already broken? Its also possible someone connecting Fans shorted 12V to Fintek FAN tacho input (two middle pins on 4 pin connector) frying all ADC inputs, in that case only replacement chip would work.

Re: Built a cheap DIY fan controller because my motherboard never had working PWM

#46

Post by bobsterlobster »

rasz wrote: post #45
bobsterlobster wrote: post #44

Earlier quoted context omitted.

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.

> Think I could wire pin 88 to ground and basically fix it? I think you could check if the pin is reliably connected to ground. Did you buy this board already broken? Its also possible someone connecting Fans shorted 12V to Fintek FAN tacho input (two middle pins on 4 pin connector) frying all ADC inputs, in that case only replacement chip would work.

>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

Re: Built a cheap DIY fan controller because my motherboard never had working PWM

#47

Post by bobsterlobster »

crote wrote: post #18
gzread wrote: post #3

Earlier quoted context omitted.

What if Windows crashes? It's better to attach a thermal sensor to the heatsink, I think.

Well, what if? We don't live in the AMD Athlon era[0] anymore. Modern CPUs are designed to boost until they hit a thermal limit, improper cooling is just going to result in a lower clock speed. [0]: https://youtu.be/UoXRHexGIok?t=55

What a blast from the past. I still remember seeing it for the first time on my Socket A Athlon 1900+ pc.

Re: Built a cheap DIY fan controller because my motherboard never had working PWM

#48

Post by realaccfromPL »

zeroflow wrote: post #7
realaccfromPL wrote: post #4

This looks really good! I am trying to do the same thing for cooling 11th gen Intel laptop motherboards with micro RP2050 board but came to the conclusion that I should just do it with ESP32 as mine has some limitations. Would you mind sharing more technical review of what you created?

RP2050 would work, as it also has the necessary built-in peripherals. ESP32 would add wifi and better ESPHome support. I suggest you stay away from the ESP8266, as it needs to do PWM in software and struggles with the 25kHz output frequency. From my experience: ESP32/RP2040 work without additional circuitry which works with most fans, but for protection, you want to add level shifters. Not all fans pull up the PWM pi…

Really appreciate your reply!!
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