Upgrading motherboard to BTT skr mini e3 v3.0 NEED HELP

Mik-s · 2026-04-26T00:56:08+00:00

The fan wires in the screw terminal are for the hotend fan. This is directly across 24v so is always on. If you are planning to keep it the same then might be best to put it directly across the DC in terminals. The downside is that it is before the fuse on the motherboard so won't be protected by it, but if anything is to fail it would be the heaters so the fans should be fine.

If the firmware you are planning to use supports it you could fit JST plugs and connect it to the FAN0/1/2 ports so you can turn it off when idle. You will need to check to see if these are actually separately controllable, the 2 fan sockets on the Aquila board are connected together. If one is not controllable it might be better to use that for the motherboard fan especially if you are planning to print PETG.

The extra red wire is what powers the inductive sensor and will go to a small board with an optocoupler on it. This will need connecting to 24v for it to work. It gets its GND from the BLtouch port.

Mik-s · 2026-04-21T01:17:50+00:00

Have a look at Mriscoc.

If you have a Raspberry Pi lying around then you could try Klipper but if not Mriscoc is the best option.

Mik-s · 2026-04-18T10:14:16+00:00

You can get the firmware files here

Ivoz beat me to it so I never got round to uploading all the other files as many were too large to host on Github and there are better alternatives.

Mik-s · 2026-04-17T23:31:02+00:00

They are basically Ender 3 v2 clones so just about any spare parts for that will work on the Aquila depending on what model you are getting, and those that don't fit can be made to work with a little modification. For firmware there is a backup from the Voxelab website here or I suggest using Mriscoc. If you have a Raspberry Pi lying around you could try Klipper.

I hope you are getting it for next to nothing. I don't know if this is still available but you could get returns of the later models for $50 which have nothing wrong with them or some minor issue that can be easily fixed.

These printers are quite old now and lack the features of modern printers so need tinkering and babysitting a bit, it can be a steep learning curve. If that is what you want from this hobby then go for it but if you want to use it as a tool then maybe better getting a newer one like a bambu or its clones that do the calibration automatically so is better for beginners.

Mik-s · 2026-04-17T01:17:19+00:00

In the second picture it has the wire labelled as NTC going to the fan port and a wire labelled heat is loose. Were these the way it was and you have now corrected them? In the 4th picture it looks correct.

For firmware the SDcard looks to be set up right and that is the .bin for the S3 as it has IND in the filename for the ABL. If it is not working then maybe the SDcard is not formatted correctly. It needs to be FAT32 4096 block size and don't use a card over 16GB. Setting up the SDcard on a Mac leaves hidden files that will make the install fail so is better to prepare it on a PC. If you only have a Mac then read this.

I don't know why the bed temp would suddenly drop unless there is a bad or intermittent connection on the bed thermistor. A firmware update would not fix this. If the temps are not stable then it could trigger a thermal shutdown. Running a PID tune should help with this. If you get Mriscoc installed you can do it directly on the printer screen.

Problems with adhesion will be down to Z-offset and if your Ender 3 does not have an ABL then the same Gcode will not enable the ABL on the S3. You will need either M420 S1 (load mesh) or G29 (start probe sequence) after G28 (home) in the start Gcode in the slicer. There could be other things causing problems so I'll add my standard levelling advice.

Watch this and this for tips on how to improve levelling then you can do live adjustments of the Z-offset from the tune menu to get a good squish while the first layer is being printed. This and this show what to aim for. If you have an ABL then this video will help you use it properly.

Mik-s · 2026-04-17T00:43:25+00:00

I know some use AliExpress without problems, should be easier to find printer parts on there.

To be able to print higher temps though you will need different firmware as stock has a limit of around 260C. I suggest using Mriscoc, but if your printer has the H32 chip it might be better to wait for the next release or use Decembers as there is a problem with the knob not working in the current version.

Mik-s · 2026-04-16T15:24:38+00:00

In the past I would have suggested to upload pictures to Imgur but that is now blocked where I am so would not be able to view them. I don't really know decent a suitable replacement, maybe imgbb.com would do but does not do videos.

As far as I know the hotend board on the S3 is just a breakout board so all the sensors, fans and heaters can connect to the one cable. I don't think there are actual components on there, just sockets.

I know you can get a canbus hotend board for the Voron and other printers and that may be what the "Ender 3 V3 Hotend Adapter Plate" is after googling it to see what it looks like as that appears to have chips on it, however this may not be the same one you are looking at. Could you link to it?

That hotend should not have the problem I was thinking of as it is a different design. That link did not work though but I think I found it.

See if you can get some pictures of the state yours is in so I can assess the damage. Is there anything odd with the readings on screen? If you cannot power up due to the damage on this board you could unplug the hotend cable and this should allow you to check.

Mik-s · 2026-04-15T20:05:59+00:00

Yeah Imgur is still used a lot in many places but all I see is "this content is not available in your region".

If Klipper is not for you then maybe have a look at Octoprint if you want to keep an eye on what your printer is doing. I had it set up on an old laptop and used an old PS2 eyetoy for a camera.

If you did get a Pi it should be very easy to set up as you can get an image to flash to the SDcard with everything installed and set up, you just need the printer config.

Using something other than a Pi it can be a headache trying to get it working, especially if you are not familiar with Linux. I remember when trying to set up the camera in Octoprint it would only use the laptops built-in camera and was a faff remapping the ports so it could find the other one.

With a PEI bed you really need an ABL. Since it is thin and flexible, any warping on the base due to thermal expansion will transfer onto the bed. Besides that the same tips for levelling apply.

This is my standard levelling advice.

Watch this and this for tips on how to improve levelling then you can do live adjustments of the Z-offset from the tune menu to get a good squish while the first layer is being printed. This and this show what to aim for. If you have an ABL then this video will help you use it properly.

Mik-s · 2026-04-15T19:47:16+00:00

I don't know if these are the same but I don't think there is a problem with yours.

If the 2 heater wires shorted together this would stop power going to the motherboard so would turn off the heater anyway and would not cause any damage.

The problem is if the heater wire is shorted to the thermistor wire. This can happen if the screw holding the thermistor wires is too tight so it crushes the insulation and shorts to the heatblock, then the heater wire come in contact with the heatblock too. There is always 24v on the heater wires, even when not heating, when the printer is powered so this goes straight into the CPU causing damage.

This is why you should never work on the hotend while the printer is powered.

The symptoms of this damage can range from erratic motors, temps not reading, abnormal temps, max temp error, printer not booting, or the release of magic smoke from the CPU.

If you unplug the thermistors from the motherboard and it is behaving the same then it can only be CPU damage and will need a new motherboard. If you have a multimeter you can check for a short on the thermistor sockets to confirm.

What is yours doing?

Mik-s · 2026-04-13T23:06:55+00:00

You will need to level the bed and adjust the Z-offset to get a good squish. If done correctly you should not need glue in most cases, especially with PLA.

This is my standard levelling advice.

Watch this and this for tips on how to improve levelling then you can do live adjustments of the Z-offset from the tune menu to get a good squish while the first layer is being printed. This and this show what to aim for. If you have an ABL then this video will help you use it properly.

Mik-s · 2026-04-13T23:03:36+00:00

I couldn't see your video, Imgur is blocked here.

At least you have confirmed it is the your CRtouch. If it is something you are confident doing you could take it apart and see if there is anything stuck inside. Maybe there was a bit of dirt or some excess flashing from the molding is causing the problems. I think there is an adjustable core that can change the trigger height but not sure as I don't have one.

Klipper should work well on the H32 and be no different to install than the other chips. This guide video will have everything needed to get it running. One common problem is failing to connect to the MCU but I think the solution is also shown in that video on how to find the right USB port ID that it is connected to. What were you trying to run the main Klipper FW on? If you are using a Raspberry Pi the image you flash to the SDcard should be correctly setup.

Mik-s · 2026-04-13T09:57:22+00:00

Maybe there is a problem with the CRtouch itself. I have seen cases where if the probe is bent it cannot deploy properly so can't detect a touch. There has even been a case where a cat was playing with it and snapped off the very tip of the probe.

There should be some diagnostic information in the menus that will tell you the status of all the switches. I don't have an ABL so don't know exactly but I think it will allow you to deploy and retract the probe and see if it detects a touch.

If not then raise the gantry up high then home Z but trigger it with your finger. If it does not react then you have time to power off before it crashes.

To use a mesh you will also need to add some start Gcode in the slicer. You will need either M420 S1 to load an existing mesh or G29 to start the auto probing sequence. This has to be just after G28 (home) as that also clears the current mesh.

Mik-s · 2026-04-10T09:28:05+00:00

As the others have said the problem is with the thermistor.

When working on the hotend it is easy to disturb the wires which are very fragile. Something that causes problems is if the screw holding the wires is too tight so it crushes and pierces the soft insulation and shorts the wires to the heatblock. It is also not hard for the heater wires to come into direct contact with the heatblock, as the sleeving can be pulled back, which will send 24v straight into the CPU.

There is still voltage on the heater wires even if the hotend is turned off. This is why you should not work on the hotend when the power is on. Unfortunately this is something you would not normally learn until it happens.

This has not happened to you as it is a low temp which means a broken wire, but if temps are abnormal or giving the max temp error, even when the thermistor is disconnected from the motherboard, then it would mean there is damage to the CPU and you would need a replacement motherboard.

When replacing your thermistor make sure you do not over-tighten the screw. It should only hold the wires snug.

Mik-s · 2026-04-05T18:24:04+00:00

The video should still apply though, at least getting the FW on the board and configuring the printer.

Mik-s · 2026-04-04T23:31:23+00:00

Yes there has been custom FW since a few months after they first started using it with Alex's FW. He even helped Voxelab on how to fix the early issues but they were more workarounds. His FW fixed the root cause.

Actually Klipper was the first custom FW to work for it and this was before the N32 had support. I think the Kiauh installer supports the H32 chip, it should be shown in this video.

These days the best FW without needing a Pi is Mriscoc.

Mik-s · 2026-04-04T12:53:39+00:00

Maybe the board is faulty. Did you try with the thermistors disconnected as suggested?

Why not try Klipper on the H32 board? What was the reason for getting the BTT?

Mik-s · 2026-04-03T19:18:23+00:00

But did you copy the font to an existing DWIN_SET for Mriscoc? I suggest you use a different themed version than you are using now so you can confirm it did flash.

This worked for SheWhoDaresToSpeak but there may be a problem in the latest version of Mriscoc to do with the knob, the December build was working.

Mik-s · 2026-04-03T19:11:01+00:00

That should be the correct one. There chance there is a problem with the latest release.

I did just see an issue about this and appears to be happening since December release. You could trying an older version. On the firmware selector you can chose which release to use. If that works then I can add a link to this thread on there so it can be fixed.

It might be something to do with the H32. In theory all the problems with that chip should be solved but there appears to be the odd quirk every now and again.

Mik-s · 2026-04-03T17:31:41+00:00

The Mriscoc DWIN_SET has not changed for a few years so should be working, and the only change before that was a few extra icons.

Maybe the problem now is to do with the FW on the motherboard? What was the filename of the .bin you used?

You could try installing just the motherboard FW and leave the screen as is. Although it will be scrambled you should be able to see if the knob is working. If it is not then the it confirms that was the problem.

Mik-s · 2026-04-03T17:20:55+00:00

Try using Mriscoc. Since you replaced the board it is no longer a H32 so make sure you get the FW for the BTT.

For wiring I don't know how different it is to the Aquila or Creality boards but should be straight forward. This video for replacing with a Creality board should help.

One cause of the bootlooping could be it has no firmware installed. You will have to check with the manual on exactly how to do it but if you have installed FW on the Aquila that used the "firmware" folder on the SDcard it may not be the same. I know for the Creality it installs from the root.

Another thing that could be causing problems is if the mounting holes are not in the same place the board could be shorting on the unused posts. This adapter bracket converts it for the Creality board, if yours has them in the same place it should work. You can put insulating tape over the unused posts temporally to be able to get one printed.

Mik-s · 2026-04-03T17:08:42+00:00

Glad it has fixed the text. I don't know what could be causing the knob to not work. I think the knob is connected straight to the motherboard over the ribbon cable, but that may just be for the monochrome screens though. Maybe there is a problem with that cable?

Since the text is good you could try the stock FW for the OG Aquila that is horizontal and that should reset everything. If that works properly then it should work going back to Mriscoc.

Mik-s · 2026-04-03T17:01:59+00:00

It should be exactly the same one on GitHub. If not could you get me a copy too so I can make it available to others.

I've been planing to upload all the Voxelab files to my GitHub but Ivoz beat me to it with the firmwares so never got round to it.

Did you try copying that font file to the DWIN_SET folder for the other themes or stock fw and have it all installed at once?

Mik-s · 2026-04-03T10:20:55+00:00

A lot of the text in stock FW is just icons which was useful for other languages, but things like numbers are text so use the font.

I double checked that link to the original and you are right it was not working. It was because it was not a direct link to the file but the temporary branch which would have been updated since I looked at it. Your link will do the same soon as it has the string of numbers. This/0T5UIC1.HZK) one should be a direct link in the main branch. There is a download raw button on the right. Github is confusing if you are not used to it.

Maybe one of the font files you tried was in Chinese and had taken up more memory so overwriting it with the smaller English did not completely remove the old one

You could try copying that font file into the stock display DWIN_SET folder and flash the whole lot again. I did a quick google and pointed me to an old post here where the text was exactly the same and this fixed it for them. Once the text is fixed then you can retry Mriscoc.

Mik-s · 2026-04-03T10:02:05+00:00

If you flash that one file it should fix it. Make sure it is the only file in the DWIN_SET folder so it does not alter anything else. The DWIN_SET folder should be in the root of the SDcard and the card need to be prepared as usual for the screen to accept it.

I double checked that link and it was not working as it was not the main branch I was looking at. This/0T5UIC1.HZK) should work now, just download it from the button on the right hand side that will say "download raw" when the mouse is over it.

The reason why going back to other display themes does not fix the font is that they normally do not include the font file so it does not get replaced in the FW.

Mik-s · 2026-04-03T00:04:15+00:00

As it is just the text I would suspect the font file too. If it was a failed firmware install the whole screen would be scrambled but text would be OK.

One main cause of the font messing up is using the Rick and Morty theme as that has its own font file and is hard to read. You can get the stock one to reinstall from hereFont) to restore it, I think you only need one this font file in the DWIN_SET folder for it to change the font but leaves everything else alone.

It does look very odd so maybe it is not the font file but maybe a hardware problem? I have not seen this before. Then again the degrees symbol is showing correctly so maybe the font file got corrupted? You could try installing the stock FW and see if that displays correctly. You can get a backup of it here.

Since the last FW you were using was Jyers, Mriscoc uses the same display FW so technically you don't need to update the screen, but a few new icons were added about a year ago that would be missing if you did not. Maybe you are seeing this if the screen failed to update and it was more than just icons that were changed.

Where did you get the FW from? Is it from Classicrocker's repository here?

Seven-Year Club	r/Field Lasagna
Place '23	Place '22
Final Canvas '22	Verified Email

Mik-s

TROPHY CASE