Question 3 pin PWM cable to 4 pin to adjust fan speed.

[Antc92]

I recently purchased a skytech prebuilt Link to the Computer. This is the motherboard:Mobo. At first I noticed that the fans weren't adjustable in the bios, I contacted Skytech and they told me that that WPM connected in the fan control board was hard wired to the top of the case (which you can't open) where there's button to control fan speed but I don't notice any difference, in fact if I hold it down it changes the RBG lights for some reason even though there's a button for that next to it. Here's a pic of my fan control board: FCB. I told them my issue and they sent me another PWM cable that goes into that empty white slot on the top left that should run to a SYS_Fan Header. Here's the 3 pin PWM cable they sent me and my system fan headers:MOBO and PWM cable. The pwm cable doesn't fit in any of the headers. Is there any way to convert it into a 4 pin? Or is it that this mobo doesn't support this certain fan control board in order to manually adjust rpms of the fans? Or am I just completely missing something? Any help is appreciated, these fans are way too loud for my liking.

 

[Karadjgne]

That cable in the 3rd picture isn't 3pin pwm.

PWM is 4 pins for the primary, 3pins for any branch. Hot, ground, sensor, pwm signal. 3/4 pin are the same connector, different amounts of wires.

That cable is RGB, for lighting, not for fan control.

The fans will have 2 wires, 1 for fan control, 1 for lighting. If they only have 1 cable, it'll be 6pin, which is proprietary to certain pcbs and hubs.

An rgb fan is for all intents and purposes nothing more than a regular fan with a light strip glued to it, 2 seperate things.

 

[Antc92]

So is it not possible to manually control my fans since these fans in particular don't plug in to the sys fan headers?

 

[~cw]

The FCB image link is broken. What make is the FCB? Does it have an internal 3-pin (voltage curve) or 4-pin (PWM) connection to allow it to run lockstep with a SYSFAN or PUMPFAN signal, which they perhaps haven't connected?

 

[Antc92]

The FCB image link is broken. What make is the FCB? Does it have an internal 3-pin (voltage curve) or 4-pin (PWM) connection to allow it to run lockstep with a SYSFAN or PUMPFAN signal, which they perhaps haven't connected?

https://imgur.com/a/4j8LFcB

View: https://imgur.com/a/4j8LFcB


Here's a new link to it, hopefully it works

 

[~cw]

Looks like Skytech use some OEM / rebranded fan controller removed from its case to fit on the back side of the case. Just be mindful that while the PC is plugged in, there will be 5 Volts and 12 Volts live to the non-insulated metal traces on that board, so don't go sticking your fingers in (or metal tools) unless you want some nasty zaps and potential problems with the PSU.

I saw someone else asking a similar question about their Skytech on Reddit - you may choose to buy your own fan controller later to eplace the basic one they've supplied. View: https://www.reddit.com/r/pcmasterrace/comments/qi68cu/skytech_rgb_question/

 

[Karadjgne]

Can't tell what the top right plug is for, but port#1 on the right side is almost always 4 wire for fan speed. #2 - #6 will be 3pin outs (no sense pin). Port#1 must be splittered? if using multiple fans personally I find it's better to use the hub for that because it will have controller limits. But I'd say you need just a plain 4pin PWM fan extension that plug into the top left, and the other end plugs into sys_fan header. It'll look exactly like what's plugged into fan port #1

 

[Paperdoc]

This is a duplicate thread, sort of - it continues on from the prior thread here

https://forums.tomshardware.com/thr...oo-loud-not-adjustable.3756502/#post-22651124

So you have received from the maker a new cable that is supposed to connect from the white socket labelled "PWM" at top left of your fan control board to the SYS_FAN1 header at top front of your mobo. But it does NOT fit! In fact, the photo #3 you linked in your first post of this thread shows the connector for a 3-pin ARGB mobo header - NOT the connector for a 4-pin mobo fan header. So if that is the actual "new" cord they sent you it is the wrong one! It is simply a duplicate of the one you already have on the upper RIGHT socket of the board, and that goes to the mobo JRAINBOW1 header near top right of the mobo.

The cable you need may well have the same connector with 3 holes on one end to fit into the fan board PWM socket. Its other end certainly should have a connector with FOUR holes in it and two ridges down one side. That would fit onto the SYS_FAN1 mobo header. Whether it has 3 wires or 4 may not matter. The essential connections for this cable are for Pins 3 and 4, and maybe also for Pin 1 - a connection for pin 2 is not needed, but all 4 wires might be present.

So, first alternative: contact the PC maker again and request that they get their act together and send you the RIGHT cable to connect to a mobo FAN header. Other alternative IF you feel capable would be to take that wrong cable and replace the wrong connector at the mobo end with a correct 4-pin fan connector. Sometimes the easiest way to do that is to get an old fan and cut off from it the cable and its connector. Then you just need to splice the wires from that connector to the right wires from the wrong cable you got. If you want to proceed this way, post back here and we can tell you exactly what wire to splice to what.