WARNING: I TAKE NO RESPONSIBILITY FOR ANY MODIFICATIONS YOU MAKE TO YOUR PRINTER.
Following this tutorial involves disassembling and modifying your 3D printer, and should not be attempted if you are not comfortable with soldering. As with any time you modify or repair a piece of equipment, you run the risk of damaging the device in the process of modifying it.
The CR-10S printer community has recently been rocked by the news of a problem the circuit board which may cause a reduction in print quality, reduce the lifetime of the printer, or even make the printer unsafe. This issue was brought to public attention by TH3D in their blog post. This post will not dive into technical details (which can be found elsewhere), but the problem stems from the use of an undersized capacitor in the 5V power circuit. This results in poor quality power being delivered to the microcontroller. The most noticeable impact of the problem is very noisy temperature readings. In the long term, the poor quality power regulation may damage the printer.
I did not discover this issue, nor did I uncover the correct fix. There is a lot of information floating around out there about potential fixes, much of it out of date or incorrect. This tutorial post documents one working method to fix your own printer. This is not the only fix possible. For those who are comfortable with a soldering iron, but don’t have the background in electrical engineering to design your own fix, this is for you.
This fix will involve disassembling the control box for your printer, removing a circuit board, then removing and replacing a capacitor. This involves soldering as well as connecting and disconnecting a bunch of small wires. This is not a terribly difficult soldering job, but it probably not a good first soldering project. The process should take about an hour, most of which is disassembling and reassembling the control box.
Tools and Parts Needed
- Creality CR-10S printer with the Version 2.0 circuit board. Other versions of CR-10S may not be affected, or may require a different fix. The board revision will be visible as a label on the circuit board.
- Soldering Iron – A soldering iron appropriate for work with small electronics is required (not a soldering gun)
- Rosin Core Electronics Solder
- Allen Keys – The assortment that comes with the CR-10S is acceptable
- Small flat head screwdriver – The one that came with the CR-10S is acceptable
- Replacement capacitor – See the capacitor discussion below
- Sharpie Marker – One or more of different colors will be helpful for keeping track of the printer wiring.
- A pair of tweezers or forceps for holding small components
Note that the CR-10S printer control box was not designed to be particularly easy to disassemble and re-assemble. As with all projects, it is important to keep careful track of each action you perform so that you can work backwards when reassembling the printer. Many of the cables inside the printer are not labeled and can be easily confused. Go through each step slowly, take photographs using your smartphone, and label each part you remove. You will thank yourself later.
I have tested two replacement capacitor candidates. Both capacitors seem to improve the temperature stability of the printer. I believe either one would be an acceptable replacement. Of the two, I observed slightly better results with the United Chemi-Con APXG160ARA221MF80G.
The second capacitor which I tested was the Nichicon UCV1V221MCL1GS. It seemed to perform well however my results show it was slightly inferior to the United Chemi-Con capacitor. It is also available from the usual sources:
The capacitors listed here are not the only ones which will work to improve the stability of the 5V regulator. However I have used this capacitor and can attest to positive results.
Performing the Modification
Step 1: Disconnect the Control Box from the Printer
Unplug your printer control box from the power cord. Remove all of the plugs from the stepper motors, filament sensor, and end stop sensors. These cables are all labeled from the factory (at least on my printer) so you don’t have to worry about mixing them up later. On the control box, unscrew and unplug the cables to the extruder and heated bed. This step is basically the reverse of the original printer box set-up, so I won’t go into detail here.
Step 2: Open the Control Box
Move the control box to a table where you have plenty of room. Gently flip the control box upside down (put it on something soft such as bubble wrap to avoid scratching the box or your table). On the bottom of the control box there are 5 screws. Unscrew these and put the screws in a safe place. The bottom side of the printer can now be removed and set to one side.
Step 3: Remove the Power Supply
Inside the printer, you should now see a large silver box with a fan vent. This is the power supply. We will have to move it out of the way to access the control board. Flip the control box gently onto its side such that the voltage selection switch is visible on top. There are four screws on this side, which anchor the power supply. Unscrew them and set them aside. When unscrewing the last screw, use your fingers to hold on to the silver power supply box as it will drop when the last screw is removed. Do not unscrew the power supply while the open box is facing upwards, this will cause the power supply to drop on the circuit board, which might damage something!
When all the screws are removed, the power supply is now loose. However there is a small metal flange (visible in the middle image above) which makes it challenging to remove from the control box. Angle the power supply and you will be able to pull it out of the control box.
Flip the control box gently back so that the open bottom is facing upwards.
The power supply is connected to the control box by many cables. You can label and remove these cables, or you can flip the power supply up and out of the way. Make sure you have something to rest it on so that you are not putting stress on the wires, this would be bad!
Step 4: Removing Cable Connectors from the Control Board
You can now see the control board inside the control box. But we can’t remove it yet, it is connected to all the other parts of the printer! To begin, I recommend taking several photographs of the cables, this way you can consult them later when you have to reassemble the printer.
Remove the two large cables connecting the control board to the LCD. These are labeled on the control board and LCD side as EXP1 and EXP2.
There is a cable tie directly above the circuit board, which zip-ties many cables together. For ease of access, you can cut the zip tie to give you more slack to work with. Be very careful not to damage a wire while cutting the zip tie.
Remove the five 4-pin cables along the bottom edge of the circuit board. These cables (and their corresponding ports) are labeled so you should be able to reassemble them easily.
Remove the three 2-pin cables along the left side of the circuit board. These cables and their ports are labeled. Also remove the three pin cable on the left side of the board.
Along the top left side are four 2-pin cables. These cables are not color coded or labeled. In order to avoid mixing these cables up, I used Sharpie markers to make colored marks on the male and female connector halves. This way, I could easily match the connectors back up when reassembling.
Step 5: Remove the Terminal Block Connections
All of the cables with pin connectors have now been removed. However there are still several wires connected to the circuit board through the green terminal blocks. I recommend taking a photograph of the circuit board for reference when re-assembling the printer.
At the top right edge of the circuit board, there are four wires connected to the rightmost four terminal blocks. To disconnect a wire, insert the small screwdriver into the screw on top of the terminal block and loosen it by two complete turns (720 degrees). The wire should now be able to be freely removed from the top of the terminal block. Several of the wires are the same color. Make sure to somehow mark the wires and terminal so you know which wire goes where.
On the right side of the control board, there are two more terminal block connectors. There should be two wires going into each connector, one large and one small. Mare sure to make note of which wire goes into which terminal block. You can loosen the screws and remove the wires to these terminal blocks.
Step 6: Remove the Control Board from the Control Box
Now your circuit board is free of all connections. You can now remove it from the control box. The circuit board is held in place with four screws. Remove these screws and set them aside. The circuit board should now be loose and can be removed from the control box.
Step 7: Remove the old C4 Capacitor
As always when handling bare circuit boards, be careful, they are delicate and sensitive to static electricity. Take the control board over to your soldering area. The capacitors on the board look like small silver tin cans. There are 9 of them on the board. C4 is the closest to the black circle saying “330”, on the side of the board opposite the SD card slot and USB port. Look at the image below for reference. Note that the top of the capacitor has a dab of color on one side. This denotes the “negative” side of the capacitor. The side without the dab of color is the positive side. Electrolytic capacitors only function correctly if installed in the correct orientation. Make sure to note how the capacitor is installed, so that you can install the new capacitor in the same orientation.
Note: The new capacitor you use may look slightly different. The capacitor pictured here is a Nichicon UCV1V221MCL1GS, however I have also tested the United Chemi-Con APXG160ARA221MF80G and found that it works.
Plug in your soldering iron. The CR-10S board uses lead-free solder, so if you have an adjustable soldering iron, set it to at least 375 °F. Once the soldering iron is up to temperature, melt a thin coating of solder onto the tip. This will help conduct heat better. Don’t put on too much, if it starts to form into a drop, wipe off the excess.
Be very careful using the soldering iron You do not want to accidently touch the hot tip of your soldering iron to any part which may be damaged by the heat. You do not want to accidently dribble liquid solder onto the circuit board, it could cause a short circuit. And of course, touching the hot part of the soldering iron to your skin will cause a painful burn.
The C4 capacitor is attached to the circuit board by two solder connections on the underside. In order to safely remove the old capacitor, we will have to melt these solder connections and move the capacitor while the solder is liquid. Luckily, the solder pads on the circuit board protrude out from underneath the capacitor. Grip the capacitor with your tweezers or forceps, but be careful not to put any force on it yet. Using your soldering iron, touch one of the solder pads until you see the solder melt (it should happen quickly, within a second or two). While the still holding the soldering iron on the solder pad, GENTLY use the tweezers/forceps to pry up that side of the capacitor. This should take very little force, and you only need to move it up a little bit. Once you have lifted the one side, move the soldering iron over to the other solder pad and repeat. This time, you should be able to gently pull the capacitor off the circuit board. If it is still stuck on, repeat the process for both pads over again. It is important to be gentle when prying the capacitor, too much force and you will rip the solder pad off the circuit board, ruining it!
Now that the old capacitor is off, set it aside.
Step 8: Solder on the new Capacitor
Now you are ready to install the new capacitor. It should look very similar to the old capacitor, so be careful not to get the two mixed up! First, use your soldering iron to remelt the solder pads and smooth them out. It may be wise to put a bit more solder on the pads, as some may have come off with the old capacitor. Be careful not to put too much solder on the pads, and make sure no solder overflows the pad and contacts another electrical component or another solder pad!
Take the new capacitor, and position it on the solder pads using your tweezers or forceps. Make sure your capacitor is in the same orientation as the old one! While holding the capacitor in place, use your soldering iron to melt one of the solder pads underneath it. The solder should attach the connector on the bottom to the solder pad. Repeat this process with the other solder pad. The capacitor should now be attached to the circuit board. If the capacitor is tilted, you can repeat the melting process on both solder pads, this should “suck” the capacitor down to the circuit board.
Congratulations, modification complete! Now you just need to put the printer back together!
Step 9: Re-connecting the Circuit Board
Place your circuit board back in the case onto the screw mounts. Use the four screws to attach the circuit board to the case. Tighten the screws just a bit, do not over tighten them or you might crack the circuit board!
Re-attach the loose wires to the terminal blocks next. The two terminal blocks on the right side each have two wires, make sure they are both inserted in before tightening the screw on top of the terminal block. On the top of the board, there are four wires which need to go into four terminal blocks. I hope you labeled them like I suggested!
Re-attach the pin connector cables. The only tricky ones are the four 2-pin cables which are not labeled from the factory. I hope you labeled them as you took the printer apart! The other cables are labeled and go to the corresponding connectors, which are labeled on the circuit board. Reconnect the two ribbon cables to the LCD last.
If you cut the zip tie holding the bundle of wires together, I suggest that you replace it with a new zip tie. Make sure the wires are not contacting any of the fans; this could cause the cable insulation to get damaged, or stop the fans spinning and cause heat problems.
Step 10: Reconnecting the Power Supply and Closing the Control Box
Once all the cables are connected to the control board, gently turn the control box on its side so that the voltage selection switch hole is facing upwards. If you left the power supply wires connected, simply replace the power supply in the case, and screw it back in. If you disconnected any wires from the power supply, make sure you reattach them before replacing the power supply.
Once the power supply is securely mounted, you can re-attach the bottom plate of the control box using the 5 screws you removed earlier.
Step 11: Reconnect the Control Box to the Printer
Once the control box is reassembled, check the voltage selection switch on the side to make sure that it wasn’t accidentally flipped while you were disassembling/reassembling. Plug the wires from the control box back into the motors, end switches, and filament sensor. The cables are labeled so this is easy. The only cable without a label is the one for the filament sensor, so you can find the correct cable by process of elimination. Make sure to plug the hot end and heated bed cables back into the control box and screw the connectors on. This process is identical to the one you went through when assembling the printer the first time.
The noise in my temperature readings was greatly reduced by this modification. Whereas previously I was seeing temperature oscillations of +/- 3°C on the hot end and bed, after the modification, I only see temperature changes on the order of 0.2 °C on the hot end, and 0.1 °C on the bed. This is much more in line with other 3D printers I have used.
Before Capacitor Modification
After Capacitor Modification (Nichicon UCV1V221MCL1GS)
After Capacitor Modification (United Chemi-Con APXG160ARA221MF80G)
Having tested both the Nichicon and United Chemi-Con capacitors, the performance is very similar. With the Nichicon capacitor, very occasionally I would see brief periods of increased temperature noise (visible in the pictures at around the 9 minute mark). I have thus far not experienced this with the United Chemi-Con capacitor. For this reason, I think the United Chemi-Con capacitor is probably superior, but if you have already ordered or installed the Nichicon, I do not think it is worth upgrading. I am not an Electrical Engineer, so take my opinions with a grain of salt.
Frequently Asked Questions
What capacitor should I use?
I have provided results here for two replacement capacitors that are readily available, cheap, and seem to fix the problem; see the Capacitor section of this post. These are not the only capacitors which can be used, but they are the only ones I have tested. I will not provide any advice on capacitor choice beyond that.
Can I use X instead of the capacitor you recommend?
Maybe. I am not qualified to say what capacitors will and won’t work. I have not tested any configurations other than the two capacitors discussed in this post.
Will you do the capacitor replacement on my printer?
No. There are already commercial entities offering capacitor replacement services. I am publishing this blog post for people who would like to replace the capacitor themselves.
Your post doesn’t go into enough detail about how to solder. Explain!
This post is not meant to be an introduction to soldering. Such tutorials are widely available and are probably better than anything I could put together. Check out electronic hobby sites like Adafruit, or video sites like Youtube. I DO NOT RECOMMEND THIS MODIFICATION AS AN INTRODUCTION TO SOLDERING. IT INVOLVES SOLDERING SMALL SURFACE MOUNT COMPONENTS IN CRAMPED QUARTERS. IT SHOULD ONLY BE PERFORMED BY PEOPLE WITH MODERATE (OR ABOVE) SOLDERING EXPERIENCE.
If you are new to soldering, don’t go away disappointed! Go purchase and assemble a beginner level electronics kit! You can find very easy kits that do all sorts of cool things such as audio amplifiers and clocks.
After reassembling my printer, the control box now makes a loud whining or scraping noise!
This is likely caused by some of the wires contacting one of the internal fans. It is important that you immediately correct this to avoid damaging the fan or the wires. Unplug and open the control box, and remove the power supply. You should be able to find which wire is rubbing on the fan and move it out of the way. Feel free to add additional zip ties to keep the wires away from the fans!
I followed your tutorial and now my printer doesn’t work any more!
This is unfortunate, but as I state at the beginning of my tutorial, I am not responsible for anything you choose to do. I am providing this tutorial as a public service to the 3D printer community which has done so much to help me. The contents of this tutorial are accurate to the best of my knowledge and ability, and where my knowledge is lacking I try to make that clear. Any time you disassemble and modify electronics, you are taking a risk. With the proper precautions and training, this risk is minimal but never eliminated. If you would like a “risk-free” option to repair you printer, I encourage you to research the commercial entities offering capacitor repair services. Keep in mind that these commercial services are not backed by the printer OEM, and any warranty you get will be at the discretion of that commercial entity.
That said, there are some things you can try:
- Re-read this tutorial CAREFULLY AND COMPLETELY. Perform the steps of the tutorial again, removing the new capacitor and soldering it back on. It is possible that the capacitor was not completely soldered on the first time, or that you re-wired the control board incorrectly when re-assembling the printer. Taking photographs and labeling wires as you go is helpful for difficult re-assemblies.
- Commercial entities offering capacitor replacement services may be willing to try to repair your control board (or not, I haven’t asked).
- Replacement CR-10S control boards are available on the internet for $100 or lower. While not an ideal solution, it is cheaper than buying a new printer. Keep in mind that replacement control boards will likely still have the same capacitor issue.
Why don’t you just pay a commercial service to replace your capacitor?
That is definitely a viable option, and probably the best option for people who aren’t comfortable disassembling their printer or soldering. Truth be told, putting together this tutorial probably took more time and effort than the extra cost of paying for a commercial capacitor replacement. But there are several reasons I preferred to do it myself:
- The commercial services currently available are not backed by the OEM printer supplier, so the fix you are receiving is not under any warranty, or somehow “better” than a fix you can do yourself.
- The cost of the commercial repairs is much higher than the DIY option, which will cost you a few dollars if you are willing to wait for slow shipping on the capacitor. Repairing multiple printers is also much cheaper to do yourself (most of the cost is in the shipping). This may be an important factor for non-profit organizations or schools which own multiple CR-10S printers.
- If you are in a hurry to get back up and printing, ordering a capacitor with overnight shipping and performing the repair yourself will get you back up and printing within 24 hours. The commercial services will likely take several weeks to send you back your repaired board.
- The capacitor issue is potentially a safety hazard. I do not agree that the fix should be kept proprietary to the organizations offering repair services when there is the potential for damage to the printer or the user.
- 3D printing in general, and the CR-10S in particular, have thrived under the open source do-it-yourself community. In fact, most of the technology the CR-10S is built on is open source (Marlin, Rep-Rap, CURA, etc). The idea that the fix for the CR-10S capacitor issue should be closed source does not make sense to me. This tutorial is being released under the open source Creative Commons license. You are free to use this tutorial, modify it, or pass it on. You are not allowed to use this tutorial for commercial purposes or to generate your own proprietary, closed source versions for sale or commercial use.
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.