Akasa PWM Fan splitters not working?

Snookums · 19 Jun 2015 at 13:52

Just got 2 akasa PWM fan splitters and neither seem to be working. Am i missing a step? Just simply connected them up and only one fan on each splitter is spinning. Any ideas?

Tealc · 19 Jun 2015 at 17:52

Maybe there's a wiring fault between the master fan and the slave fans. Seems unlikely that both would have the same fault though.

Which fan is spinning?

Are they all 4 pin PWM fans?

Snookums · 19 Jun 2015 at 20:29

both the fans plugged into the 4 pins are spinning the 3 pins are not. I'm highly doubting a manufacturing error too. The fans work fine as well tested without splitter.

Tealc · 19 Jun 2015 at 23:08

They aren't really meant for 3 pinners. Were you expecting fan control or just a means with which to run your fans at 100%?

Snookums · 20 Jun 2015 at 07:40

Sorry I meant all my fans are 4 pin but the 4 pin fans plugged into the 4 pins aren't spinning at all.

doyll · 20 Jun 2015 at 13:20

Check the continuity of the power and ground wires. My guess is one of them is not completing the power circuit from plug to socket. If the were manufactured one after the other it is quite possible for several in a row to have the same problem.

Tealc · 20 Jun 2015 at 16:43

The Akasa splitter is a very poor design with multiple wires stuffed into a small connector cavity so what Doyll says could very well be true. It would have been better (but would have cost more to make) they'd used an inline splice or two to join the wires.

Snookums · 20 Jun 2015 at 22:05

Cables are braided so it's hard to see any wiring issues/defects but from what I see they seem fine. Ugh already issues with these arriving three days late now they are DOA. Wonderful.

Tealc · 22 Jun 2015 at 12:32

Snookums said:
Cables are braided

Might be a different splitter than I've seen then. The one I have (and never used) is just a tangling mess of single insulated cables.

Ah the Flexa one. Still has the very same issue with all PWM wires stuffed into one tiny terminal designed for 22-24 AWG that will take 20AWG at a push. It just shouldn't have 5 individual wires stuffed into a single terminal. No wonder you have issues.

Anyway grab a multimeter and check the Pin 4 connections between the master connector and the other connectors. Then check the power and ground between the Molex and the other connectors.

doyll · 22 Jun 2015 at 13:26

LOL
The braided ones just put braid over each of the wires and heat shrink on each end so there is little or no flexing except at pin connection. After a dozen or so flexes the wire starts to fatigue and breaking off of pins.

AgedIdiot · 22 Jun 2015 at 13:40

If memory serves - you need to connect for power (molex or sata - dependent upon which Akasa splitter we are talking ) then you need to connect the connector marked as cpu header (or something like that) to the motherboard cpu fan connector and lastly you connect whichever fans you want to run at the same speed to the other connectors..
Am running 4 x 120 fans with mine without any probs ( so far anyway!) .
Check board that it is playing PWM?

Hope the above helps

doyll · 22 Jun 2015 at 16:08

AgedIdiot said:
If memory serves - you need to connect for power (molex or sata - dependent upon which Akasa splitter we are talking ) then you need to connect the connector marked as cpu header (or something like that) to the motherboard cpu fan connector and lastly you connect whichever fans you want to run at the same speed to the other connectors..
Am running 4 x 120 fans with mine without any probs ( so far anyway!) .
Check board that it is playing PWM?

Hope the above helps

Only thing I can add is fans run at percentage of PWM duty cycle, not a specified RPM. The PWM signal controls fan speed, and RPM sensor reads RPM signal from fan, but motherboard PWM circuitry does not set the PWM signal percent based on RPM is based on percent of PWM percentage.

I don't know if any of the newer motherboard are different, but even if they do use rpm to set PWM, it is only for the master fan on the PWM splitter. All other fan speeds are based only on PWM signal and how their individual PWM to RPM curse are programed on their respective PCBs.

For example here is Thermalright TY-147, TY-147A and TY-143 Both TY-147 & TY-147A are same 1300rpm fans with different PCBs on different PWM to RPM fan curves. TY-143 is 2500rpm and appears to have same PWM to RPM curve as TY-147, but because it is 2500rpm instead of 1300rpm at max speed, the RPM at each PWM signal rate gives TY-143 a much higher speed on same PWM signal rate going to TY-147. TY-147a with different PWM signal rate to RPM program on it's PCB has a different curve than TY-147. Hope that makes sense.