Followup: Observation. I placed a voltmeter on one of the other Molex-plugs, and noticed that everytime the pump pulses the voltage dropped to <5V (ie. probably close to 0V). I then connected 3 fans to the powersupply at the same time, and the effect is so pronounced that I can hear the fans die momentarily, then resume. The powersupply is old; it's an AT-powersupply and as such does not need the jumper. I have successfully run 2+ harddrives on this supply without other load, as well as the thre...

Ref: dead aquastream - red LED blinks continously I just got a new pump, and it exhibits the same behaviour; no difference with or without the deaeration jumper and pulsing every 1.6 second (instead of pumping continously). I can feel this pulse on the outgoing tube for the first 5-10 cm (high attenuation), but I can't feel it on the intake. I've gotten the air out of my system already, but the water doesn't come squirting out of the radiator vent (instead it flows slowly). The water coming out ...

No. I have not actually timed it, but this is how the duty cycle appears: [on - 0.7 sec] [off - 0.3 sec] Everytime the light goes off there is a very very soft jolt, as if the electric engine tries to go over 2-3 "peaks" (as is common with electric engines). But it does not commence continuous operation. The deaeration pin is not present. However I suppose this is how deaeration is supposed to work? Maybe it's stuck in deaeration mode despite the hard-reset? I have access to a second computer, a...

Manual: Zitat Initial operation The red status LED on the rear side of the pump should now lighten up for approximately three seconds and then be turned off again. (The LED might also be blinking, depending on controller configuration.) If the LED is permanently switched on, the pump controller has detected a malfunction. In this case, please perform a reset as described in chapter 9.1. 9.1 describes the hard reset that I tried with the jumper on deaeration during power-on.

I have the one on the picture; yellow backplate with molex, pins, etc.

I have now come to the stage where I let the computer stay on for ages with the pump running. However from what I can tell the pump does not start. The red LED blinks continously. I followed the troubleshooting step in the manual, and did a factory reset. The jumper is not present during launch. To reduce the chance of any issues I have removed all other cables but power. What is the next thing to try? What is the pump trying to signalise?