Blinking Red BLTouch

Hello everyone and lets hope for today to be a good day!
Unfortunately, i require your assistence today as my mischievous little shite of a sensor!
I have the 5 wires coming FROM the sensor TO the printer mobo which is correctly wired according to the matching colours on each cable. I have double checked with the guide i was following when installing the sensor. Just to make sure i didnt follow the ALDI guide. The biggest reason id like to get it to work is that i have NOT a single print with the printer since i first started dabbing with the sensor.
Practically the sensor itself is brand new because i ordered it, tried to install but didnt get it to work and in the middle of the installation aswell as a print. Kinda paused the 3D printing hobby because life needed some focus. I then moved to a new house which had me pack the printer down into a storage box so i didnt need even to loose a single screw… Fast forward 2-3 years and here and been for the last couple of days trying to stand on my own feet. Still with the old Smart v2.0 sensor thats… well practically new, since i havent even done a single print with the sensor as a bed leveler.
Maybe i were unlucky and just got a defect one?

  1. Checked the 5 cables from sensor that then travels to the printer motherboard.
    Im must be colourblind or nothing is wrong with it (pretty sure im not colourblind tho)

  2. As soon as i start the printer the probe blinks only red.

  3. In the top middle of the LCD screen, I can see picture of a BLTouch probe, it is grey which im not sure is correct. Also When i go into Tuning>Sensor the ONLY thing that makes the probe even react is the Reset button. If i press Deploy, Stow or Self-Test nothing happens and the probe continues to blink

The Z-height menu does work tho

Wanhao Duplicator i3 Plus

    "24volt Edition"   
   "E3D Titan Aero"
   1.75mm FULLSIZE E-step motor 
  "Custom Laser cut"
  3.5mm thick Stainless steel plate 
  #design by kimmo
   "BLTouch Smart"

Hi Didden,

Welcome to the community!

A blinking red BLTouch indicates that it is failing its internal self test. This is generally caused by a wiring issue or because you have a faulty sensor. If everything is wired according to the directions in the ADV i3+ guide for your printer, it is still possible that you have a bad connection. Double check any Dupont connectors, as those can be unreliable, and the connection to the BLTouch itself. Also, check that any installed pins are clean and don’t have any flux or other residue they may have picked up during installation. Check the full length of the cable runs with a multi meter if you have one to make sure the physical wiring is good.

Also, check the sensor itself to make sure the pin moves freely. You can try to move it manually, or remove the screw on top which will allow you to remove the pin and inspect it more closely to make sure its clean and is not damaged or deformed. If you do remove it, make sure you re-insert it in the correct orientation as the pin has a flat side and will jam if not inserted in the correct orientation. If you do find a problem with the pin, you can get replacements. They are pricey for what they are, but much cheaper than a new sensor.

If you’re confident the wiring is correct, the connections are good, and the probe is mechanically ok and clean, you may just have a defective sensor.

Hello SilverSurfer and thanks for the reply! I apologize for how poorly written and confusing the text might be as I accidentally posted before I had the time to properly formulate myself and make the text understandable.

I will do a full reinstall, fresh new cables and resolder everything, before I decide to reflash firmware to the non-BLTouch version.
I will first try to connect the short original wires coming from the BLTouch JST connector “directly” to the correct pins on printers circuit board. Yes, this could be tested using a multimeter but just until now, I dont trust mine anymore.