Hello,
I have a problem with AXIS version with heatbed an dual extrusion. I did a few successful prints but today suddenly the main power supply went wrong. Screen went black, motors, everything turned off suddenly. Main power adapter light was somehow dimmer. I checked both power adapters and cables are ok. The computer board works when connected via USB. The Marlin software starts. But it doesn't start when power plugged in. Only I've noticed that the no matter which power adapter I use the light on the adapter is dimmer as if there was some weird power consumption from the device.
I checked the cables inside if anything was loose, I disconnected power cables from board, connected again like in tutorial but it seems like something is wrong with the board itself.
Please advise how to check whats the reason of malfunction.
Hi,
Thank you very much for the answer! This step by step instructions should be handy any time I have problems with printer.
I checked once again the mainboard visually, chcecked the cables if anything didn't go loose while printing. I didn't start to disassemble since it worked fine for few prints. And I found the source of malfunction. Its the A4988 Stepper Driver where the capacitor burned. I don't know why. But since there is a spare one in the box I could easily replace this one.
Everything now works fine. Except dual printing but that's another case.. still the printer can't really replace the filaments correctly. Always one of them gets stacked.
Thanks again. Just to show below there is an image of burned capacitor /dark smudge on the soldering/ on the driver.
If the light illuminates normally when not plugged in you should be able to check that it's sending the correct voltage with a multimeter. If it is showing ~24v then I'd start by disconnecting everything, including the stepper drivers and connections to motors, the connection to the LCD, etc, and then adding back one thing at a time. I know it doesn't sound fun but it would be the best way to eliminate things.
There could be a short somewhere. If you remove everything such that it was just 24v in you could start adding each of the following (disconnecting the power between each step):
Chassis fan
LCD
Hotend
Heated bed connection
Part cooling fan
The bed thermistor
Hotend thermistor
Limit switches
Stepper drivers
Stepper motors
I tried to list the items in order of direct connection to the power or what would draw a lot of current or alert you to an issue. If you plug it in the chassis fan should come on immediately. If it doesn't do this when nothing is connected then I'd be highly suspect of the power supply. If it's both of them doing it then... really bad luck? The LCD comes on when the power comes on. If the chassis fan runs then the next logical thing on power up that could cause an issue would be the display.
The next items are high current items. The hotend shouldn't be directly linked to the PSU until the printer instructs the board to give it current. This connection might tell you if there is something wrong with the board, it's always attempting to give full current to the hotend, or something is shorted. I don't think it's likely but this is where I'd go next. You can carefully investigate the hotend to make sure it isn't heating up without being told so.
The same goes for the heated bed. The way this is designed is that current is pulled from the mainboard but that the mosfet "closes" and lets the current go to the bed from the second power supply. If connecting the mainboard to the heated bed assembly causes issues try keeping the bed unplugged. It might be something bad in that assembly. Again, I doubt this because it isn't something that should be getting current right when the printer turns on but it doesn't hurt to check.
The part cooling fan, thermistors, and limit switches shouldn't cause any issues. However, if you haven't had issues to this point it's probably OK to connect them.
The stepper drivers, the little boards that are plugged in on the right side of the mainboard, can be added back one at a time. Remember their orientation and turn off the power before adding each one. Next do the same which each stepper motor.
Hopefully you can stop at step one with no fan coming on and it's just a set of faulty supplies. A nice upgrade for the printer would be a good Meanwell 300w power supply so that we could forego the dual power bricks and have just a single connection to the printer.