Hi Mario_pic, Congratulations, you fixed it. Sorry I didn't see your previous post about whether you can use a 0 ohm resistor. That should be fine, but I caution you that the current flowing through the 0 ohms resistor can reach several amps. Make sure (check the resistor datasheet) if it can safely carry the high current. I just soldered a bridge (small piece of wire) directly across the two paby gjt211 - Controllers
Hi all, As I read more and more through this fantastic forum, I continously find bed levelling causes many headaches to many people (including myself!). I have an idea... I would like to discuss it with anyone interested. I want to implement auto bed levelling using micro stepper motors. Now let me explain my thinking. There are many micro stepper motors available for very reasonable prices arby gjt211 - Mechanics
Hi again Olaf, The setup is using a 4 line by 20 character LCD with LED backlighting. The entire setup powered is using 170mA from the 12V supply in idle mode (no steppers or heaters switched on). It drops to about 160mA with USB plugged in. I doubt the regulator is having trouble with that kind of current draw, it should be good for about 1 amp. The board that is giving me troubles is made byby gjt211 - Prusa i3 and variants
Hi Olaf, Well it looks like my excitement has been short lived. It has started doing it again about 30 minutes after writing the post claiming it was working! But I am aware this is how things work, do something, looks like it's fixed, tell the world, then it falls in your face! I tried adding several uF of capacitance directly at various locations on the 5V rail across the board near the procesby gjt211 - Prusa i3 and variants
Hi Olaf, Very good points Olaf, both of them tend to point towards the solution I ended up implementing. In the past I would normally have access to some very expensive test equipment (I'm an electronics R&D engineer) so I could troubleshoot the fault. I suspected the fault was related to the 5V supply but couldn't prove it without an oscilloscope. It looks like I have fixed the problem thoby gjt211 - Prusa i3 and variants
Hi Willy, I had a similar problem with my MKS Gen board. I ended up fixing it by putting a 3300uF capacitor across the 5V supply rail. I actually had one laying around from my R/C hobby (used for my flight controller to stabilise the supply) and just plugged it into one of the 5V headers on the MKS GEN board. I can't believe how well it worked, I have not had any weird issues since with resets oby gjt211 - Controllers
Hi topbun, did you sort this out yet? If not, I may be able to help. Let me know, I had the same problem.by gjt211 - Firmware - mainstream and related support
Hi mario_pic. Have a look on your MKS Gen board for two small surface mounted electronic parts labelled LG1 and LG2. Get your multimeter and measure for continuity (or ohms) through each one. More than likely LG2 has gone open circuit. LG2 provides the ground/0 volts connection for the stepper drivers. Without the ground, the stepper drivers float up to a higher voltage from the motor supply (1by gjt211 - Controllers
Hi all, I purchased a Sunhokey Prusa i3 kit, duly assembled it and it has been working well for some months now (although the MKS Gen board fried itself a couple of months ago, replaced it). I have a weird problem, when I press the "Home" button in Repetier. Normal operation 1. X axis moves towards home position 2. X axis triggers the endstop for home position and stops moving Abnormal operatiby gjt211 - Prusa i3 and variants
Hi Kybb, Not sure why the case of your PSU is at +12v, it shouldn't be. Did you manage to find anything checking inside? With that in mind though, I would advise anyone to use a multimeter set to ohms or continuity and measure between the positive and negative outputs and the metal case of the power supply just to check. Ensure the power is disconnected before doing this! The way switching poweby gjt211 - Prusa i3 and variants
Hi Ledaero, Yes, I connected the AC earth to the DC negative. Maybe there is someone out there that can advise why this shouldn't be done. The reason I done this was just in case of earth potential rise between my PC and the MKS Gen board (which is what fried my first board). My USB cable is 5m long and now my PC and my printer have a solid earth connection between them via the AC power cable, nby gjt211 - Prusa i3 and variants
Hi flynn, Thanks for your response, but unfortunately this is not my problem. This can happen within seconds of being powered on before the stepper drivers even get a chance to warm up. I also have both types of stepper drivers (A4988 & DRV8825) and it happens with either of them set at various current levels as well. My drivers also have an 80mm fan directly cooling them as well. Kind regaby gjt211 - Prusa i3 and variants
Hi Kybb, mine did the same thing after a few weeks. I replaced the main control board and all the stepper drivers. I have since repaired the main control board but all the stepper drivers were not able to be repaired.by gjt211 - Prusa i3 and variants
Hi all, I am not sure if here is the right place to post, but I have been trying to reverse engineer the MKS Gen control board as supplied with my Sunhokey Prusa i3 acrylic kit. My background is in electronics research & design for 15+ years. My Sunhokey acrylic Prusa i3 kit was working well for a few weeks, then one day it just fried itself. There are two inductors connecting various groundby gjt211 - Prusa i3 and variants