Question Prebuilt PC system fans are too loud. Not adjustable

[Antc92]

Hey! I recently purchased this prebuilt: Skytech Chronos Gaming PC Desktop – AMD Ryzen 5 5600X 3.7 GHz, RTX 3060, 1TB NVME SSD, 16G DDR4 3200, 600W Gold PSU, AC Wi-Fi, Windows 10 Home 64-bit.Link to the Computer off of Amazon because it was on a really good discount. It starts up fine but I noticed the fans are extremely loud. Only the CPU and GPU fans rpms are adjustable in the bios not the system fans. I called skytech support and he had me play around with the fan control board but no luck, it actually turned off one of the rgb lights for the fan after adjusting. The fan speed button on the case also doesn't work as well, It only changes the RGB lighting when held down which it is not suppose to do. The skytech rep support told me he most likely is going to send me a new fan control board but I rather not go through that process if I don' have to. The motherboard is a B550M PRO-VDH WIFI (CEC). Any help with this is appreciated. thank you

 

[Paperdoc]

You may or may not have a faulty component. But first, let's check the connections and the ways you are trying to use this.

That board appears to be a combination of a fan MOTOR Hub for speed control and a fan LIGHT Controller to power and control the light displays in the fan frames. Fan motors and lights are completely separate devices although both are mounted in one unit. This board is made so you CAN use fans with ARGB lights in their frames (as supplied with the computer) with a mobo that has NO means of controlling lights. BUT if your mobo does have that ability (and yours does) the board has an option to let the mobo do that lighting control job.

The board requires several connection cables already installed. Check that they all are connected properly. Referring to your photo, at the bottom the wider connector with 4 wires brings power in from a SATA or 4-pin Molex power output connector from the PSU. Next to that is a 2-wire cable that goes to the case's front LED pushbutton. At the top end there are two cables, one with 2 wires and one with 3, but I cannot read their labels correctly. ONE of these will go to your mobo's JRAINBOW1 header at top near the front. See your mobo manual p. 40. The other will go to one of your mobo's SYS_FAN headers (p. 36). NOTE exactly which SYS_FANn header.

If all those cables are connected properly, now go into BIOS Setup. We need to ensure that the mobo SYS_FAN header involved here is configured properly. See manual p. 58. On that screen at upper right choose the particular SYS_FAN header the board is plugged into. Then on the far left choose the PWM Mode, not DC or Auto. Right below that set the Temperature Source to Motherboard, not CPU. Use Esc to get back to Main Menu, then F10 to get to an Exit Menu where you choose to SAVE and EXIT. This will save those settings and reboot. This ensures that the mobo will send to that fan board the PWM signal it needs to control fan speeds.

Now we'll look at light controls. The system is intended for basic use to let you manually control the light display options by pushing the case LED button to make any changes. In fact, it may well go into that mode every time you reboot. But because your mobo DOES have the JRAINBOW1 header and you have a cable connecting that to this board, you can change this method of control. On most systems like this if you HOLD DOWN that case LED button for 5 sec or more it will tell the board to turn over LIGHTING control to the signals it gets from the mobo. Then you use the MSI software utility Mystic Light to configure lighting controls.

So that's two areas of adjustment. One is to ensure the mobo fan SPEED controls get to the board and on to your fans. The other is to allow the mobo LIGHT controls to do their job instead of using the case pushbutton.

 

[Antc92]

You may or may not have a faulty component. But first, let's check the connections and the ways you are trying to use this.

That board appears to be a combination of a fan MOTOR Hub for speed control and a fan LIGHT Controller to power and control the light displays in the fan frames. Fan motors and lights are completely separate devices although both are mounted in one unit. This board is made so you CAN use fans with ARGB lights in their frames (as supplied with the computer) with a mobo that has NO means of controlling lights. BUT if your mobo does have that ability (and yours does) the board has an option to let the mobo do that lighting control job.

The board requires several connection cables already installed. Check that they all are connected properly. Referring to your photo, at the bottom the wider connector with 4 wires brings power in from a SATA or 4-pin Molex power output connector from the PSU. Next to that is a 2-wire cable that goes to the case's front LED pushbutton. At the top end there are two cables, one with 2 wires and one with 3, but I cannot read their labels correctly. ONE of these will go to your mobo's JRAINBOW1 header at top near the front. See your mobo manual p. 40. The other will go to one of your mobo's SYS_FAN headers (p. 36). NOTE exactly which SYS_FANn header.

If all those cables are connected properly, now go into BIOS Setup. We need to ensure that the mobo SYS_FAN header involved here is configured properly. See manual p. 58. On that screen at upper right choose the particular SYS_FAN header the board is plugged into. Then on the far left choose the PWM Mode, not DC or Auto. Right below that set the Temperature Source to Motherboard, not CPU. Use Esc to get back to Main Menu, then F10 to get to an Exit Menu where you choose to SAVE and EXIT. This will save those settings and reboot. This ensures that the mobo will send to that fan board the PWM signal it needs to control fan speeds.

Now we'll look at light controls. The system is intended for basic use to let you manually control the light display options by pushing the case LED button to make any changes. In fact, it may well go into that mode every time you reboot. But because your mobo DOES have the JRAINBOW1 header and you have a cable connecting that to this board, you can change this method of control. On most systems like this if you HOLD DOWN that case LED button for 5 sec or more it will tell the board to turn over LIGHTING control to the signals it gets from the mobo. Then you use the MSI software utility Mystic Light to configure lighting controls.

So that's two areas of adjustment. One is to ensure the mobo fan SPEED controls get to the board and on to your fans. The other is to allow the mobo LIGHT controls to do their job instead of using the case pushbutton.

Hey paperdoc thanks soo much for the reply and useful information. I followed your steps and got up to the part where you mention about the top two cables, one with the 2 wires and one with 3, one of them is plugged into the JRAINBOW1 header you mentioned but it looks like there's nothing plugged into any of the mobos SYS Fan headers, could that be why system fans aren't adjustable in the bios? I took a better picture of the top so you can see the labels .

 

[DRagor]

The 2-pin cable is labeled MB SW. I suppose it is connected to front panel then? And the header next to it labeled PWM is the one that should be connected to motherboard fan header I guess.

looks like there's nothing plugged into any of the mobos SYS Fan headers, could that be why system fans aren't adjustable in the bios?

That is correct. The only way motherboard can even know there are any case fans is when they are connected to mobo fan headers. Does not matter if connected directly or via hub, but there must be a connection. So if your hub is not connected to motherboard then motherboard can't control fans connected to hub. Normally it is not big issue if you can control fans from front panel but you mentioned it does not work too. Actually, I checked this PC online, and the pictures show the case has only 3 buttons. Big one is surely power switch, then there is small labeled LED which I guess should change lights, and then another small one without label - is it Reset or is it the button that should control fan speeds?

 

[Antc92]

The 2-pin cable is labeled MB SW. I suppose it is connected to front panel then? And the header next to it labeled PWM is the one that should be connected to motherboard fan header I guess.

That is correct. The only way motherboard can even know there are any case fans is when they are connected to mobo fan headers. Does not matter if connected directly or via hub, but there must be a connection. So if your hub is not connected to motherboard then motherboard can't control fans connected to hub. Normally it is not big issue if you can control fans from front panel but you mentioned it does not work too. Actually, I checked this PC online, and the pictures show the case has only 3 buttons. Big one is surely power switch, then there is small labeled LED which I guess should change lights, and then another small one without label - is it Reset or is it the button that should control fan speeds?

The small unlabeled button is for fan speed. I actually figured it out. The PWM cable that should be connected to the SYS Fan header was actually routed into the case where that unlabeled fan control button is. They swear that that the button changes the fan speed but it's not noticeable. The case actually can't be open to retrieve it so said they would send me a PWM cable that can go into that empty slot on top of the fan control board which then goes into the MOBO. Thanks guys for the feedback I appreciate it.

 

[Paperdoc]

Good! That is the solution - getting the right cable to plug into a mobo SYS_FAN header.

However, WATCH OUT for how this new cable is to be attached. It does NOT go to that 2-pin connector that already has a small wire to it. It will go instead to the three-contact white connector beside that which now is not in use. It has the label "PWM" beside it.

I am intrigued about what that unlabelled small pushbutton on the top is. They told you it should change fan speeds but it does not, right? Does it do NOTHING? I ask because what is missing on that case is a Reset button which most computers have. It would look like that one. But IF it were connected properly to a set of pins in the mobo Front Panel header, it would cause a complete RESET when you push it. It is POSSSIBLE that there is a two-wire cable hanging down from the top front which is NOT plugged in anywhere but ends in a two-hole small connector labelled RESET. IF you find that, post here and we can advise where it SHOULD be plugged in on your mobo to give you that Reset function for that button.