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I install an AIO H115i ELITE no Capellix.
At the end of the Y-cable, it has :

  • a Sata alimentation,
  • a usb for CM,
  • 2 fans connectors and
  • a 3 pin named LHE.

But I only see one wire in this pin corresponding to ground. No second or third son (for 12V and RPM signal).
Is it normal to have a 3 pin with only one cable ???

My motherboard does not start. I tested the 3 pins on the FAN CPU connector and on the IO_PUMP or PUMP_HEADER connector. No boot.

If you installed an H115i, tell me where to put the 3 pin and it's normal to have onlye one cable in 3 pin

Thanks berofehand




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1 hour ago, FR-FLo said:

My motherboard does not start. I tested the 3 pins on the FAN CPU connector and on the IO_PUMP or PUMP_HEADER connector. No boot.

Why does it not boot?  CPU fan error?  Or something else?


That single wire connector is the tachometer wire. Its sole function is to send a rpm signal to the motherboard to satisfy the standard “must have something on cpu fan” to boot protocol. It has no effect on the AIO’s operation but if the pump does not talk back to the bios it will throw up the cpu boot error as a warning something is wrong. As such, it is supposed to go to cpu fan. All those AIO_Pump and W_Pump headers are standard chassis fan headers set to 100% by default for basic AIO units that get their power from the motherboard. Nearly all AIO units get their power from SATA these days. On most boards those specialized headers can be unlocked and turned back into functional fan headers if needed. CPU and OPT are special and don’t do anything very well except run air cooling fans on fast trigger values. Not good for case fan use. Perfect for parking the dummy tachometer wire. 

If you are getting the CPU fan boot error, set cpu fan to “disabled”, full speed, or whatever language the bios uses for constant 100%. This should not matter on a tach only wire but some users report it does on their board. Obviously if the cpu temps are aggressively ramping up in the bios, the pump is not running and there is a problem. If the cpu temps are steady and still getting the boot error, you can disable the boot protection in the BIOS. The exact method varies by board maker but generally involves setting the CPU fan monitoring or RPM to “ignore” or disabled. That will allow you to boot and then you can get into CUE and see if there is a further issue. 

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