PSU Failed TWICE!!!  

Re: PSU Failed TWICE!!!

Is it possible there's a short circuit somewhere in the printer? The purpose of a fuse is to cut the power before something even worse happens, so maybe the PSU fuses are working as designed.

Re: PSU Failed TWICE!!!

Is it possible there's a short circuit somewhere in the printer? The purpose of a fuse is to cut the power before something even worse happens, so maybe the PSU fuses are working as designed.

I'm gonna assume this didn't happen immediately on hookup, as I've read about this... This is an actual failure of the PSU... supposedly.

The fuses in these shouldn't blow. They exist mostly to prevent fires in the event of a short in the PSU.

I wonder.

It seems the majority of PSU issues are happening on 120v.

I beleive it's a 200watt (or 250watt) PSU... and I read somewhere that when both the bed, and nozzle are on, the PSU runs at 100%+.

I wonder if the 240v input circut, is less prone to this?

Example: converting 240v to 24v is a 10:1 ratio. let's say 240 watts. 240 watts @ 240v is 1amp. 240 watts @ 120v is 2amp. wire amp ratings are based on the gauge of the copper wire itself.

I wonder if something on the "input" side of the power supply can't handle the current @ 120v, and it can at 240v. That would explain the limited number of failures as well.

Re: PSU Failed TWICE!!!

I posted in an earlier thread if all the failed PS's were on 110 and they were. I then asked if there were any failed power supplies on 220 and no one chimed in.
I have an unused 220 outlet in the garage that I've cleared space for my printer. I'm going to build and test my first 100 hours there. Once I know it works well I'll bite the bullet and move it into the house where I had originally planned to place the printer on 120v.
If it fails then I'll know it's something in the 120v connection.

I'm new to 3D printing, but I was in test and evaluation so I know how to put something through the wringer...

Re: PSU Failed TWICE!!!

I've had two bad ones as well. My first died after a month (fuse blown, wouldn't supply voltage with a replacement fuse), a week for replacement. My second never worked well: when it was under significant load [heat-bed] it would randomly drop voltage to 0v and reboot the system. Trying the 2nd replacement now, we'll see.

I've been printing with a 350W MeanWell PSU off of Amazon. Overkill on wattage, but I'm hoping that margin buys me some reliability. It also doesn't have the clicking or rattling sounds that Prusa acknowledges their PSUs have. I'll probably stick with that and use the Prusa PSU as backup.

On a positive note, shoot them a note or chat with support on the website. They'll ship a replacement off within 3-4 days and you'll be up again in a week.

Re: PSU Failed TWICE!!!

I posted in an earlier thread if all the failed PS's were on 110 and they were. I then asked if there were any failed power supplies on 220 and no one chimed in.
I have an unused 220 outlet in the garage that I've cleared space for my printer. I'm going to build and test my first 100 hours there. Once I know it works well I'll bite the bullet and move it into the house where I had originally planned to place the printer on 120v.
If it fails then I'll know it's something in the 120v connection.

I'm new to 3D printing, but I was in test and evaluation so I know how to put something through the wringer...

I could be wrong but US 220 is different than EU 220 in that we use two 110 hots and a neutral where they use one 220 hot and neutral.

Re: PSU Failed TWICE!!!

curious, mine has been fine. I am in the US and I may have 120V or maybe even 125V as my house voltage tends to stay pretty high.

I read about the rattling power supply before I took delivery so I prepared by purchasing some RTV162. Before I assembled the kit I disassembled the power supply and glued the plastic insulation sheet with this silicone and also dabbed some other areas, augmenting what was already there.

This is not significant in relation to failures but my power supply has not had any rattles : )

What might be significant is that the screw terminals did not seem to be very tight. I don't know what would have happened if I had not done the tear-down and rebuild. The additional board that is used for power panic makes the assembly of the supply a little bit tricky. I think there is risk of problems simply due to wire management problems.

That said, I still think it is really odd that two power supplies would fail. This is either very bad luck or else something is a little bit off with your printer or else maybe you run different conditions? I mostly print PLA but I have done a few prints with PolyMaker PC-Max. The slic3r settings call for bed temperature 110C and nozzle temperature at least above 250C as I recall.

Are you typically printing really high temperature things? Of course I would not 'blame' that but just looking at anything that could help point in the direction of root cause.

Re: PSU Failed TWICE!!!

I posted in an earlier thread if all the failed PS's were on 110 and they were. I then asked if there were any failed power supplies on 220 and no one chimed in.
I have an unused 220 outlet in the garage that I've cleared space for my printer. I'm going to build and test my first 100 hours there. Once I know it works well I'll bite the bullet and move it into the house where I had originally planned to place the printer on 120v.
If it fails then I'll know it's something in the 120v connection.

I'm new to 3D printing, but I was in test and evaluation so I know how to put something through the wringer...

I could be wrong but US 220 is different than EU 220 in that we use two 110 hots and a neutral where they use one 220 hot and neutral.

Steve, I'm aware of this, but I can't simulate EU220, just start with what I have available. Also I might get a good PS, but I don't think I want to pull it apart and modify it because of any warrantee no matter how short it might be. Anyone know how long the warrantee is?

Re: PSU Failed TWICE!!!

curious, mine has been fine. I am in the US and I may have 120V or maybe even 125V as my house voltage tends to stay pretty high.

I read about the rattling power supply before I took delivery so I prepared by purchasing some RTV162. Before I assembled the kit I disassembled the power supply and glued the plastic insulation sheet with this silicone and also dabbed some other areas, augmenting what was already there.

This is not significant in relation to failures but my power supply has not had any rattles : )

What might be significant is that the screw terminals did not seem to be very tight. I don't know what would have happened if I had not done the tear-down and rebuild. The additional board that is used for power panic makes the assembly of the supply a little bit tricky. I think there is risk of problems simply due to wire management problems.

That said, I still think it is really odd that two power supplies would fail. This is either very bad luck or else something is a little bit off with your printer or else maybe you run different conditions? I mostly print PLA but I have done a few prints with PolyMaker PC-Max. The slic3r settings call for bed temperature 110C and nozzle temperature at least above 250C as I recall.

Are you typically printing really high temperature things? Of course I would not 'blame' that but just looking at anything that could help point in the direction of root cause.

I know I'm not doing anything unusual. Just PETG, 80-90C bed, 235-250 nozzle. No excessively long prints, but the print that failed it was probably 2-3 hours in.

I wouldn't look for a deeper pattern here. The PSU should be a rock-sold component. I've never had a PSU fail on my ultimaker or Rostock in years of printing. I suspect when Prusa jumped to 24V they either picked a supplier with some quality control issues, or picked a supply size that didn't have enough margin against the load. A percentage of them are therefore failing.

While waiting for my various Prusa replacements, I've been running just fine with a standard 24V supply, no apparent issues. All supplies have been running off of conditioned power.

Re: PSU Failed TWICE!!!

Looks like I also just experienced a PSU failure. (Running 120Vac, I am in the U.S. and been running the MK3 since Jan 27, so 2 weeks and 2 days.) I just finished diagnosing while chatting with online support at Prusa. My PSU fuse blew, but the fuses on the Einsy board were fine. They had me check those as well.

I have shipped off an email with several photos to Prusa for them to review - but my assumption is that they will send a replacement PSU.

Rick

Re: PSU Failed TWICE!!!

Looks like I also just experienced a PSU failure. (Running 120Vac, I am in the U.S. and been running the MK3 since Jan 27, so 2 weeks and 2 days.) I just finished diagnosing while chatting with online support at Prusa. My PSU fuse blew, but the fuses on the Einsy board were fine. They had me check those as well.

I have shipped off an email with several photos to Prusa for them to review - but my assumption is that they will send a replacement PSU.

Rick

They should quickly send you a replacement. If you are in the US, it's taken a week from first contact to PSU received for both of my replacements.

My 3rd PSU is installed now and working fine. I'm using it to print parts for a holder for my reliable PSU as I don't trust the Prusa PSUs to last, and I'm nervous next time it blows it will damage my Einsy. I'll keep the prusa PSU as a backup or for other hobby work.

When I switch, I probably won't use power-panic. My current stand has space for it, but I'm connected to a UPS anyway so it seems a bit pointless. The one time I used it my print starting point wasn't perfectly aligned. It allowed the print to finish, but there was a clear line where the power went out. Seems like a cool idea, but not very useful if you have reliable power.

Re: PSU Failed TWICE!!!

Sorry guy's. I started this thread and didn't receive any notifications. Heres the latest on my issue. I'm still in back and forth mode with Prusa. They wanted me to check resistances to determine if the einsy was shorting. All resistances are normal and match the ones on the EINSY I purchased for a future build. Support is dragging because Every time I reply to an email, it goes in the back of their queue. So it will be 48 hours or so since my last communication. That's frustrating as hell.

So I decided to replace the fuse and give it a try. Previous experience told me it would blow instantly. It did..... In a fiery fashion. The thermistor on the board literally exploded. Sparks flew. Luckily I did not have the EINSY hooked up to the PSU. As bad as this thing blew, it's hard to believe it's not a fire hazard.

So I decided to order a Mean Well PSU until this gets sorted out and I get a reliable working PSU from Prusa. My bad luck continued because Amazon packed the replacement PSU tightly in a box with no padding. The wire post block was bent like hell. So hopefully they won't drag their feet on replacing that one. Bad luck!!

Re: PSU Failed TWICE!!!

The US adds two 120V legs to get to 240. This makes no difference. Frequency may vary from 50-60Hz, but in reality this should make little to no difference, and certainly not cause any permanent harm to the hardware.

As long as the polarity is correct you should be fine.

On the other hand, I'm not sure engineer.

Re: PSU Failed TWICE!!!

The US adds two 120V legs to get to 240. This makes no difference. Frequency may vary from 50-60Hz, but in reality this should make little to no difference, and certainly not cause any permanent harm to the hardware.

As long as the polarity is correct you should be fine.

On the other hand, I'm not sure engineer.

The circuits in household and office buildings for general use are around 120VAC. There is 240V at the main panel but that would not be available except for a specially-wired appliance such as the stove, clothes drier or AC unit.

I don't know if we can be certain the 120V vs 240V is the root cause because this is the English forum and we don't have visibility to the statistics worldwide so far as I know. However it is a very good theory and I've seen this issue in one other product.

What is the "thermistor" that has been mentioned? Anyone have pictures? I continue to print successfully with no power supply issues but maybe I am on borrowed time?

Re: PSU Failed TWICE!!!

The US adds two 120V legs to get to 240. This makes no difference. Frequency may vary from 50-60Hz, but in reality this should make little to no difference, and certainly not cause any permanent harm to the hardware.

As long as the polarity is correct you should be fine.

On the other hand, I'm not sure engineer.

The circuits in household and office buildings for general use are around 120VAC. There is 240V at the main panel but that would not be available except for a specially-wired appliance such as the stove, clothes drier or AC unit.

I don't know if we can be certain the 120V vs 240V is the root cause because this is the English forum and we don't have visibility to the statistics worldwide so far as I know. However it is a very good theory and I've seen this issue in one other product.

What is the "thermistor" that has been mentioned? Anyone have pictures? I continue to print successfully with no power supply issues but maybe I am on borrowed time?

Have you ever had a piece of equipment that shuts itself off for a few minutes until it cools down due to overheating OR an over amperage condition? That is controlled by a resettable thermistor. Scroll down the page below the link.

https://shop.prusa3d.com/forum/original-prusa-i3-mk3-f30/power-supply-failure-t13443.html#p66027

Re: PSU Failed TWICE!!!

The US adds two 120V legs to get to 240. This makes no difference. Frequency may vary from 50-60Hz, but in reality this should make little to no difference, and certainly not cause any permanent harm to the hardware.

As long as the polarity is correct you should be fine.

On the other hand, I'm not sure engineer.

I agree. I have a coffee roaster that pulls a ton of power on 120V with no problems. It pretty much maxes out a 15amp circuit. Yes, on power hungry equipment it's easier on the components to run 240v because it pulls half the amperage, but a power supply is designed to handle 120V loads. Look at all the gaming computer PSU's out there that are in the 1000-1400 watt range. The only thing to blame here is just cheap components and maybe Prusa chose an underpowered PSU. I'd love to find out.

Re: PSU Failed TWICE!!!

The US adds two 120V legs to get to 240. This makes no difference. Frequency may vary from 50-60Hz, but in reality this should make little to no difference, and certainly not cause any permanent harm to the hardware.

As long as the polarity is correct you should be fine.

On the other hand, I'm not sure engineer.

The circuits in household and office buildings for general use are around 120VAC. There is 240V at the main panel but that would not be available except for a specially-wired appliance such as the stove, clothes drier or AC unit.

I don't know if we can be certain the 120V vs 240V is the root cause because this is the English forum and we don't have visibility to the statistics worldwide so far as I know. However it is a very good theory and I've seen this issue in one other product.

What is the "thermistor" that has been mentioned? Anyone have pictures? I continue to print successfully with no power supply issues but maybe I am on borrowed time?

I'm aware, just letting the other speculators know how we get 240 here. I may install an outlet next to my breaker to avoid this issue.