Power Supply failure  

Re: Power Supply failure

One difference between the Prusa PSU and a Meanwell is that the Meanwells are actively cooled. I proactively added cooling fans to my PSU. I used two 12 v 40 mm quiet fans wired in series, powered by the PSU and mounted on the outside near the top of the PSU to exhaust warm air. The fan holder simply plugs into slots in the PSU case. The fans are on the outside, so that the air flow should not disturb the print bed. The fans draw 0.035 amp, which is a negligible extra load on the PSU.

fans I used: https://www.amazon.com/gp/product/B000VRVHFO/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

Spend a little extra on ball bearing or FDB fans. The cheap sleeve bearings do not last.

Re: Power Supply failure

One difference between the Prusa PSU and a Meanwell is that the Meanwells are actively cooled. I proactively added cooling fans to my PSU.]

You may want to consider blocking some of the mid-level vent holes. That PSU was designed to breathe as a whole, so addding the fans like that will only increase airflow near the fans. With marginal change near the bottom. If you block the vents in the middle, it will force the fans to pull air in from the bottom, and over the entire interior. That is it will turn the case into an air duct.

But still, what you really need to do is experiment with a temperature probe. Have a probe, (electrically insulated) inside the PSU, and run a 2-4 hour print with no fans. Then repeat the same print with the fans on and with each reconfiguration. Ideally you’d want to find which component gets the hottest, and make sure the ducting approach managed that component’s temperature.

I’d be interested in trying this myself, except my stock PSU is dead, and the replacement Prusa support said I would have by the end of last week hasn’t even shipped yet...

Re: Power Supply failure

Just had the power supply on my most recent MK2S go up in smoke tonight. Dunno if this is related to everyone else's issues, as the MK2S is 12v.

A little bit concerning to say the least. Glad I was near the printer and could smell the smoke. Was printing polycarbonate, 265c nozzle and 100c bed. That's a good bit of power, but should be within normal limits. Never been an issue on past machines. I've got 3 MK2S's, and the one that failed is my most recent purchase, from January of this year.

Re: Power Supply failure

Not sure if we're still keeping count of the MK3 Power supply failures or not, but mine died about a day ago. Printer was in use for a little over a month, had about 370 of actual print time on it. Blown main fuse by cord socket. Replace the fuse and still no voltage on lines to the control board. Will see if I can get a replacement from Prusa.

A little more info on my setup:
In the US, so 120 VAC
My printer is in an Enclosure, but not sure if that matters considering I had many more hours on it then some other's that have failed.
Was about 3 hours into a 4 hours ABS print - 100C bed and 255C extruder

I've also been having CRASH DETECTED Y. Didn't happen at all during the first couple of weeks, then occasionally for the next couple weeks but with no real impact on the part. In about that last day before the Power supply died this was still happening but would now result in a sight layer shift. Could the more severe Y Crashes that ended up be layer shifts have been an indication that the power supply was starting to fail. Maybe not supplying enough power and the result was that one of the stepper motors (in my case the Y) wasn't operating properly.

Re: Power Supply failure

Got the new power supply installed and re-printed my last part that had completed (the print before the job the PSU failed on) and that had a layer shift. Left Crash Detection on with the intent of seeing if false crashes and layer shifts would be no more with a higher power PSU (or at least one that isn't starting to fail).

The re-print had a layer shift of about the same size and at a similar height. This says that the stock PSU has nothing to do with false crashes and layer shifts.

Turned off Crash Detection and printed the part for a third time. This time was successful, no layer shift. Will leave Crash Detection off because a lot more success will be needed before I can conclude that turning Crash Detection off takes care of the layer shift problem.

Re: Power Supply failure

My MK3 PSU popped a fuse. Have so many orders piled up I didn't want to bother troubleshooting so swapped it for a meanwell PSU after reading this thread. Will go back and re-check it in a week or two hopefully. I received it the last week of Feb.

Re: Power Supply failure

While it is relatively easy, I have posted a "how to" in the mods area. This is using the RSP-320-24 meanwell supply, but the LRS-350-24 should work as well. Files are listed in the how to thread.

https://shop.prusa3d.com/forum/user-mods-octoprint-enclosures-nozzles--f65/alternate-power-supply-meanwell-rsp-320-24-t15707.html

Re: Power Supply failure

My power supply has also failed, popped a fuse, replaced it and it's dead still.

I have been waiting for a while now for email support to help me out. Someone in the chat said I'd get a new one but still nothing, very slow.

Re: Power Supply failure

Slowly PR should run out of power supplies ... No wonder shipping new MK3 is delayed 😆

Re: Power Supply failure

i saw an allegation on a facebook group that a new power supply is in testing , and may ship soon !! i am waiting on my assembled mk3 i3 , and have been on the fence about scoring a maxwell pre-emptively - - my printer was initially estimated to ship the first week of april , i suppose that another few weeks will not be excessively onerous - - i do have a filament pen , and other hobbies - -

Re: Power Supply failure

Hey Edward,

I think that you’re referring to my post of a few days ago. I contacted support about my soon-to-be-shipped order and asked about the PSU. They said that “in a couple of week we will be receiving a new one and they would start their testing of it”. I did not ask for dates and he did not provide any.

Based on this I decided to hold off on buying the meanswell psu and go with whatever they include. If it dies on me, I hope that the new replacement they’ll send will be the already tested psu model.

Re: Power Supply failure

The meanwell NES is loud as hell when the fan is on.

But that's not the worse of it, it has a high frequency constant sound when it's on that's super annoying, i can hear it from another room. and when the fan goes off i can probably hear it from outside.

Do not buy I'd say.

Re: Power Supply failure

Is Prusa doing a failure analysis on failed PSUs? If not, I wonder if there's some way for some other members (preferably in/near California to keep shipping costs reasonable) to donate some broken ones to me for teardown.

Re: Power Supply failure

I'm on day 10 of a broken PSU.

Prusa email is no longer responding, they only did once and all they did was stall and ask me to measure the voltage. Chat support asked me to send an email as well.

This is just terrible terrible customer support, It's like you don't even care.

Re: Power Supply failure

Is Prusa doing a failure analysis on failed PSUs? If not, I wonder if there's some way for some other members (preferably in/near California to keep shipping costs reasonable) to donate some broken ones to me for teardown.

I heard a rumor they were. When my PSU failed, I was told they would send me a return label for the dead PSU, I took it as confirmation that they wanted to perform a postmortem. Of course the replacement arrived without said return label, and nothing in email. So maybe the rumor remains unconfirmed.

Re: Power Supply failure

Day 22 of broken stock PSU for me so far. I do hope they find out the cause of this issue.

Re: Power Supply failure

Woke up this morning to take my print off the bed (was a 26 hour print). Found out that with about 4 hours left, the printer just died and shut off. Smoke detector over the printer didn't go off or anything, and the power supply didn't smell burned or anything. Just wont turn on.

Will have to check the fuse when I get back home and see if that does the trick.

Re: Power Supply failure

Mine just died during the wizard. I did a self test which passed. Upgraded firmware. Started the wizard which then started a self test again. I ran upstairs and came back down and it was dead. RIP. Prusa is replacing the PSU.

Re: Power Supply failure

Have a broken PSU, if @NiHaoMike or anyone else wants to tear it down, let me know by PM or emailing elm[remove]oret at gmail.

Re: Power Supply failure

I'll receive a Meanwell NES-350-24 power supply tomorrow. Do I need to migrate a power panic board of some kind into it from the Prusa Power supply, or is the "power panic" sensing located somewhere else?