I think I killed my PSU
I think I killed my PSU tonight. The print fan on my i3 MK2 was shutting off when the extruder would move to the right side of the print bed while printing then come back on when the extruder moved back towards the left side. I reached back with the scraper I use to remove prints from the bed to try to jiggle the fan cable where it comes out of the back of the extruder assembly to see if it was loose. I saw a spark in the PSU and the printer shut off. It won't turn back on now. Maybe I touched the PSU with the scraper but would that kill it?
I looked at the RAMBO board and the 3 fuses on there and they look fine. The power bar where I had the PSU plugged in works fine with other devices. No circuit breakers on the power bar or the house power were tripped.
Is my PSU dead and I need a replacement?
Re: I think I killed my PSU
I think I killed my PSU tonight. The print fan on my i3 MK2 was shutting off when the extruder would move to the right side of the print bed while printing then come back on when the extruder moved back towards the left side. I reached back with the scraper I use to remove prints from the bed to try to jiggle the fan cable where it comes out of the back of the extruder assembly to see if it was loose. I saw a spark in the PSU and the printer shut off. It won't turn back on now. Maybe I touched the PSU with the scraper but would that kill it?
I looked at the RAMBO board and the 3 fuses on there and they look fine. The power bar where I had the PSU plugged in works fine with other devices. No circuit breakers on the power bar or the house power were tripped.
Is my PSU dead and I need a replacement?
Sounds bad. Next time use a non conductive tool, sorry for that 😈
What maybe happened is that the PSU fuse went of touching something and the case. Nice thing about the Prusa i3 MK2 desgin is, that you have ground everywhere!
1. Unplug the PSU from main power
2. Check the PSU fuse
2.a. you can use a multi-meter using the diode/shoutcut function to check the fuse
3. If the fuse is ok, unplug the PSU from miniRAMbo (to make sure not to break it)
4. !!! Warning, be careful with the 12V plugs, it is electricity !!! Plug PSU main power cord in and make sure that the miniRAMbo plugs don't touch anything before switching the PSU on.
5. Use a voltage/multi-meter to check the power outlets going to miniRAMbo
5.a. make sure the the voltage meter is set to DC and higher than 12V usually 20V
6. If you get on both plugs (main and bed) 12V, your PSU should be fine, otherwise you have to check the miniRAMbo
7. Take the miniRAMbo fuses out and check them with the multimeter
8. If that is still not working, IT'S REALLY BAD NEWS
I guess that your fan is going off and on again depending which direction the x-axis goes, is a bad contact or broken wire.
Re: I think I killed my PSU
Fortunately, the PSU is generic and it's easy to find replacements. One example: https://www.amazon.com/gp/product/B01IMOS20A
Re: I think I killed my PSU
shane.h is right. They are very generic. I have a spare one. I suspect Prusa bought and supplied a bad batch. See recent posts about power supply problems.
Nigel
Life is keeping interested and excited by knowledge and new things.
Re: I think I killed my PSU
Hello everyone,
I just wanted to post an update as I solved my issues and hate it when people online never post how they fixed their problems!
I did indeed kill my PSU...but I brought i back to life! I removed the PSU from the printer and opened it up to discover I had just blown the fuse inside. I replaced the fuse, reinstalled the PSU and it powered back on with no issues. I also ordered a replacement blower fan since that was what I was investigating when I accidentally killed the PSU. My printer has been back in action for a couple weeks and is printing well.
Thanks for all the responses and suggestions from everyone who replied.
Re: I think I killed my PSU
and hate it when people online never post how they fixed their problems!
Thumbs up! I love when people come back to report their solution 😀 Thanks.