Ender 3v2 BLTouch blinking red

[Michael]

Hi everyone,

i followed the video tutorial by Drvax and installed the BLTouch. Everything works fine thanks to his good tutorial.
but now the BLTouch sometimes fails to home at the start of the Print. It happens total randomly at any point of the grid.
I uploaded a video where you can see what is exactly happening.
hope someone can help to fix this issue

cheers Michael

[Creed17]

I have this exact same issue with my Ender 3 V2. It fails at random points and is very inconsistent. Have you found a solution to this yet?

[irvshapiro]

Interesting. I have not seen this and unfortunately do not have an answer. The first thing I always check is if the cables are all tight. Intermittent issues are often loose cables and the connections for the BLTouch on the control board are loose to start with.

[mochalatte]

There was one time when I saw my BL-Touch blinking at startup when I turned on the printer. It still functioned properly, but just kept blinking. It blinked at a slower rate than shown in Michael's video above. A Google search turned up that one cause is that the BL-Touch attempts to drop its pin at startup a couple of times and if it fails to do so it blinks the error. In my case all I had to do was power cycle my Ender to fix the issue. Perhaps my nozzle was too close to the bed to drop its pin the first time I turned it on? But I don't know.

[FearLesOne]

My Ender 3V2 also seem to be experiencing this same problem with a newly installed BLTouch v3.1.
It is currently running the Marlin firmware v2.0.X.14 from smith3d.com (slow probe 5x5).
Many times the auto leveling would not complete at random spots and sometimes even auto home would exhibit the problem.
I have double-checked my setup for loose wires but it does not appear to be the issue; but just in case, I will be replacing the extension wires when a replacement arrives.

Posting here to show that this problem may be wider spread than not and still looking for a solution.

[Gramps]

My new Bltouch v3.1 is also experiencing this issue. I have the Dupont connectors hot glued in plus the wires are tie wrapped. From my research it appears to be a connection issue. I ordered some 4s battery balance connectors with pigtails which I believe is the same connector that is used on the board. Assuming the connector is correct I will cut the Duponts off and solder the balance connectors. The should eliminate a loose connection as the issue. In my case I also think it might be possible that the pin is sticking which I'm not sure how to fix.

[rsonnicksen]

Gramps, My BL just started doing this, but it was after I modified the startup code to hold the nozzle to 175 during mesh calib. Probably not related.
BUT...Are you saying the connectors that come with the BL are not compatible (designed to work reliably) with the connectors on the Ender3 V2 board. If so, could you give some more details, (photos, links to purchase connectors, etc. Thanks. I did think it a bit "fishy" when Irv commented how loose this connection was.

[Gramps]

The connector I used is sold as a balance connector for a Lipo battery. This is what I used to make the end that will plug directly into the plug on the motherboard. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

The top connector is the one I added the bottom one is the one that goes to the Bltouch I didn't touch it.

[wmyhal]

I always have this problem with the first print of the day. I think what is going on is the under bed has reached temperature but the class has not. It seems that after a couple of times the glass has becomes warmer and its good for the rest of the day.

I have been thinking that Ill do a test by pre-heating the bed for 10 minus before starting a print. Just try test my theory. The reason I think this is what's happening is because in the morning the room temp is down to 13c and the printer is cold.

[rsonnicksen]

So what exactly is causing the BL to fail? Do we know the critieria for pass/fail. That would certainly help in diagnosing the problem.

[Geit]

I always have this problem with the first print of the day. I think what is going on is the under bed has reached temperature but the class has not. It seems that after a couple of times the glass has becomes warmer and its good for the rest of the day.

I have been thinking that Ill do a test by pre-heating the bed for 10 minus before starting a print. Just try test my theory. The reason I think this is what's happening is because in the morning the room temp is down to 13c and the printer is cold.

I am doing the same and you are right. Especially when using an enclosure this can be an issue as the standby temperature and the printing temperature are very different. With an open printer the effect is less big, but still there, as the bed, the springs and the screws transfer heat from the bed away. Every part that transfers heat is changing in size and therefor changing the printing z height in some way.

For the same reason your level you bed and setup the z offset, when everything is heated up.

[Zardozer]

It's most likely a wiring issue. If you look on the antclabs website, there are docs for what the blinking lights mean. I did have some trouble myself with intermittent issues at times, and I tracked it down to the extension where I crimped dupont male connectors. The wires are quite thin, so any dodgy crimping job will make it less reliable. When this joint was further into the loom and it moved back and forth a lot with the movement of the carriage, it would make the connection be intermittent. The other point of unreliability would be using dupont connectors and forcing them into the jst plugs. I re-crimped to have proper jst connectors, and it never fails there.

[Ender5r]

Connectivity issues are why I replaced the Dupont connector on my BLTouch with a geniune JST. Before inserting the crimped connector pins into the connector, I made sure to test them with a continuity checker. So far, so good.

[rsonnicksen]

Ender5R, Can you provide details on what you ordered, and a quick summary of install procedure? Thx. My BL just started blinking. I'm doing a print now, and the first layer looks like it adhered ok, but I don't want to fight this in the future. I loved how my BL made the printing process magnitudes more reliable, but now...... Thx in advance for your help. R

[Gramps]

I rewired my extension cable eliminating the Dupont connectors and replaced it with the proper JST-XH connector. I cut off the Dupont connectors and soldered on the JST_XH connector.


The completed connection.


I also used some hot glue to make sure the connector stayed tight.

After this it still failed on the 1st bed level. Probe error showed on Octoprint. Reset and this time it was fine and the print started. After the print was finished. I removed it from the bed and cleaned it. I then went to the printer console and did a bed level, it failed. Powered off and back on, Bltouch would not go through it's self test. Powered off and pulled the pin down, powered on passed self test. Again did a bed level from the console and it completed. Did another one and it failed. Same issue could not restart the printer unless I pulled the pin down. I'm thinking my issue my issue now is a sticking pin. I'm sending it back for a replacement, we'll see it that corrects the problem.

[Ender5r]

Gramps , remind me, this is a genuine BL Touch, right?

There is 1 major difference between my setup & yours: I used the Z Endstop connector instead of the last 2 pins on the BLTouch connector.

[Zardozer]

I've had the pin be a bit "sticky" before, and it will indeed flash red if it can't deploy properly. It was slightly jammed up in there, maybe slightly bent, so I put it back into shape and it's deployed properly since. You can also get replacement pins if you break one. They're somewhat fragile and can be knocked around if you have a print failure where it hits something, for example.

[Ender5r]

My fear of having the pin stick is what led me to triple check that I had the BLTouch body mounted exactly perpendicular to the bed. I was pleased to see that Creality sent a spare pin as part of the kit.

[Gramps]

Ender5r yes it a genuine Bltouch, even checked the QRcode

If the new one does the samething I'll try wiring it like yours and see what happens.

The pin in mine was stuck out of the box. When I 1st turned it on the BLT blinked red until I trying pulling the pin out before powering up. Didn't check to see if it was perfectly perpendicular but I will.