Parts in question:
EK XRES 140 Revo D5 RGB PWM Pump
ASUS ROG Z390 Maximus XI Hero (Wi-Fi)
The Pump had been working fine for the last 2 months running off the CPU Fan header. Unfortunately it was discovered that a bank of fans were not operating possibly due to the fan hub breaking/shorting. It was then discovered that the chassis fan 2 header was not functioning (as the fan hub may have caused this, the fan hub is no longer used). In the process of sorting this out, every fan header was tested with each device that requires a header, and the EK PWM pump came along for the ride. This means that at some point the pump was probably booted in "DC mode". This should not be an issue in my experience, but I'm including this point as it may be relevant.
So while the chassis fan 2 header seems to be completely inoperable, this MB comes with enough headers that it isn't really an issue, and now all fans and pump are running on functioning ports.
However the issue has now arisen that the pump is not operating at 100%. Supposedly the pump when not plugged into a header at all should run at 100%, according to EK's website - https://www.ekwb.com/shop/ek-xres-14...m-incl-sl-pump
This is not what is happening. The pump is at most running at around 50% (and I suspect lower than that). I have some experience with water cooled PC's, and running my personal PC (the PC in question is a friend's PC) I have found the pump very rarely needs to go above 60%, so I suspect that this pump is only running below even 50%. There is still some PWM control of the pump, however as mentioned it's 100% setting is nowhere near "true" 100%, and I suspect that I'm only able to control the pump between 20% and say 40%. I.e - setting 100% gives 40% power, setting minimum (20%) drops it to around 20%. I obviously cannot be certain as to the true values, but there is some limited control. The pump also fails to provide any RPM information via the PWM header.
Has anyone experienced anything like this? The pump is only 2 months old, and until all of the header changes, it was running perfectly fine, so it seems extremely odd to me that there would be an issue like this. I've tested the lines from the header to the pump itself, and there is a signal getting through, so it's definitely not a signal issue (particularly given the limited control as well). If anyone has any ideas it would be greatly appreciated.