Re: Power Supply failure
prusa ships 2nd day air for replacement parts, for me they were faster than i could order one delivered by amazon prime.
I got my first replacement from Prusa a solid week after contacting them (Texas, US). It's been a week since my replacement came (non-functional), and they haven't shipped the 2nd replacement yet. It may be 2 day air, but in my case it is often 3-4 days before they decide to replace it.
I was up and printing two days after the first fail with an Amazon delivery.
Re: Power Supply failure
For those that had a power supply go bad, were any of them connected to a UPS?
Yes, both of mine were on a UPS. First one failed during a long PETG print after a solid month of good service. My second one never worked, it would drop <5v randomly, usually just after the bed started heating.
Actually, my first one was connected to a UPS, but on the 'protected but not battery backed' part. However, I had no power glitches around the time of fail (no clocks/computers had reset, my wife was home and no lights flickering).
On the "circuit droop" possibility: I doubt it in my case. It was the only printer running, and it was on a 15A circuit in a new house with no other significant load. I don't get lights flickering or anything. Even at peak current (full draw through the 3ohm bed), this should not draw more than 300w, and 2-3 amps leaves lots of headroom on a 15A circuit.
Re: Power Supply failure
For those that had a power supply go bad, were any of them connected to a UPS?
Yes, both of mine were on a UPS. First one failed during a long PETG print after a solid month of good service. My second one never worked, it would drop <5v randomly, usually just after the bed started heating.
Great to know. I have a newer UPS that I'll use anyways, but like I said I was just trying to look for additional causes. I've got a lot of time to wait for my MK 3, about 5 weeks so I guess I'm getting board...
Re: Power Supply failure
So I decided to put a watt meter on the printer to see its power usage when preheating. My printer uses 280-290 watts while heating the bed and hotend at the same time. Since the power supply seems to be a 240 watt power supply this does not seem to be good at all. I have been not using my printer because of this problem.
How can the power supply be so overloaded and still function correctly? I guess this is why we are seeing the failures start to show up.
Re: Power Supply failure
So I decided to put a watt meter on the printer to see its power usage when preheating. My printer uses 280-290 watts while heating the bed and hotend at the same time. Since the power supply seems to be a 240 watt power supply this does not seem to be good at all. I have been not using my printer because of this problem.
How can the power supply be so overloaded and still function correctly? I guess this is why we are seeing the failures start to show up.
I'm not an expert but a PSU rating is for what it's outputting, if you're measuring the PSU's wattage that it's using it's going to be higher than the rating because it's not 100% efficient. Are you measuring from the wall to the PSU? You should he measuring the output to compare to the rating and not what the PSU is using from your outlet.
Re: Power Supply failure
So I decided to put a watt meter on the printer to see its power usage when preheating. My printer uses 280-290 watts while heating the bed and hotend at the same time. Since the power supply seems to be a 240 watt power supply this does not seem to be good at all. I have been not using my printer because of this problem.
How can the power supply be so overloaded and still function correctly? I guess this is why we are seeing the failures start to show up.
Amm...i did all these measurements some posts above...
And, it seems that you don't quite understand principle of switch-mode power supply, so let me explain:
There is no such thing as ideal power supply and our PSU is no exception. Stated power (240W) is maximum OUTPUT power. Because our PSU is not ideal, it has at most 80% efficiency, so if you calculate 240 * 1.2 = 288W. You measured 280-290 W which is quite OK. When heating up PSU is as it seems close to it's max, but this lasts only a few minutes, later on power is considerably smaller, so i dont' see any reason to panic.
Re: Power Supply failure
So I decided to put a watt meter on the printer to see its power usage when preheating. My printer uses 280-290 watts while heating the bed and hotend at the same time. Since the power supply seems to be a 240 watt power supply this does not seem to be good at all. I have been not using my printer because of this problem.
How can the power supply be so overloaded and still function correctly? I guess this is why we are seeing the failures start to show up.
Amm...i did all these measurements some posts above...
And, it seems that you don't quite understand principle of switch-mode power supply, so let me explain:
There is no such thing as ideal power supply and our PSU is no exception. Stated power (240W) is maximum OUTPUT power. Because our PSU is not ideal, it has at most 80% efficiency, so if you calculate 240 * 1.2 = 288W. You measured 280-290 W which is quite OK. When heating up PSU is as it seems close to it's max, but this lasts only a few minutes, later on power is considerably smaller, so i dont' see any reason to panic.
You are completely right. I totally forgot that no power supply can be 100% efficient. I had read about the multiple power supply failures here and got scared about mine. I feel like an idiot now because I did know about the efficiency, it just completely skipped my mind while I was doing this testing. Thanks for reminding me about that, I feel much better using my printer now! 😀
Re: Power Supply failure
I'm not sure, but i have the feeling that mostly US models of PSU fail... that ones have 110V and thus double primary current...
Anyway, just print a much as you can while printer is under warranty. It would be "silly" not to print because you fear that PSU will die. If it must die, let him die under warranty, it will be definitely cheaper for you... 😀
Re: Power Supply failure
So I decided to put a watt meter on the printer to see its power usage when preheating. My printer uses 280-290 watts while heating the bed and hotend at the same time. Since the power supply seems to be a 240 watt power supply this does not seem to be good at all. I have been not using my printer because of this problem.
How can the power supply be so overloaded and still function correctly? I guess this is why we are seeing the failures start to show up.
If you are measuring at the wall, that seems about right. If you are measuring >240 watts on the 24v side, I would check the resistance of your heatbed and make sure it is >= 3ohm.
Re: Power Supply failure
Switched mode are best sized such as they are 2 times the rating where the PSU spends most of its time - efficiency etc is irrelevant, generally they're most efficient at the 50% load mark so if your PSU normally operates at 200W when doing what it should (not idling !!) then you need a 400W max rating. The efficiency isn't a straight line in any case, it is poor at max rating and when you're not pulling enough, a typical efficiency curve is steep and the ends and flat in the middle.
A PSU operated constantly at its rated maximum is a failure waiting to happen, all kinds of analogies are possible, plenty of stuff out there on the web for those prepared to look. Drive your car at the red line constantly and you'll figure this out pretty fast.
And you could easily see 240W on the 24V DC side given that the heated bed at 3 ohms is 8 Amps (ohms law not guesswork) which equates to 192 watts and the hot end heater is 30W according to E3D that's 222W without steppers in the mix which can peak at 2 amps each and will if your print has lots of rapid direction changes. The failures could be a collection of circumstances - low ambient making heaters work harder, high temperature on hot end and bed, rapid direction changes or even too much heat in an enclosure perhaps.
Using the argument that everything doesn't peak together is a dangerous one and one that experienced engineers don't use.
At 240W rating with an efficiency of 80% you're pulling 300W from the wall and 20% goes as heat, it doesn't mean you can pull 300W from the PSU for any length of time reliably.
Jo reckons they did their homework and so far my PSU has 110 or so hours on it and stays cooler than expected, it also doesn't make a lot of noise. It seems to rely on the capacitors far too much - which is the thumping / popping or whatever you want to call it but without the info that Jo must have it's performance is guesswork, there is no spec / datasheet for the PSU anywhere on Prusa site that I've found so far.
Re: Power Supply failure
I finished building my printer last night, and when I plugged it in and turned it on nothing happened except an led in the power supply and one on the einsy by the usb port lit up. After looking online this thread seems to have the best answers but I did see something suggesting I check whether it is set to 110 or 220. Only problem with that is, I can't find the switch between the two. Does anyone know where it is on the power supply? If it's just set incorrectly (not surprising considering it's built in europe) than I'd like to set it right and see if that fixes it before I break something.
The psu auto switches i believe. have you talked to chat support? if you have lights on the psu and the einsy my guess would be you have the display cables installed upside down either on the back of the lcd or in the einsy
Yep, talked to them in chat and I swapped the cables. Works good now.
Re: Power Supply failure
Power supply failure here as well. Printed great the first day. Then it went to preheat and rebooted. Did a factory reset and made it all the way to first layer calibration and rebooted again. Sent a message to support and waiting to hear back.
Re: Power Supply failure
Power supply failure here as well. Printed great the first day. Then it went to preheat and rebooted. Did a factory reset and made it all the way to first layer calibration and rebooted again. Sent a message to support and waiting to hear back.
Interesting, you have "mode 2" of the power supply fail.
Mode 1 is outright failure. Prints fine for a while (a month in my case), then dead. Blown fuse and/or blown supply. 0V out. Several folks have had this one.
Mode 2 is "weak PSU" mode. This happened on my replacement, but I haven't heard others mention it. The PSU outputs 24V and can generally run things just fine. However, it is marginal on the current it is able to supply. When pre-heating the nozzle, I'll see it drop to 20-22V, and when heating the bed it can sometimes drop all the way to zero (or below 5V), low enough to reset the board. Since the board resets, the bed turns off, and the PSU then pops back to 24V again (no load!).
I managed to make it half-way through a print before it reset, so it isn't always immediate.
I'm still waiting for them to ship me my 2nd replacement, it's been a week since I contacted them. Running with a different supply (which is rock solid at 24.1-24.2 V while idle or heating bed and nozzle).
Re: Power Supply failure
So my PSU just failed. Nothing as dramatic, but about 30 minutes into a typical ABS print with stock Slic3r settings I head a small pop and the printer was dead. I verified the fuse was blown and was hopeful that was the extent of the problem.
Unfortunately when I replaced the fuse, I powered on the printer and nothing happened. There was a *very faint burning smell so I immediately disconnected power. I have not disassembled the PSU and will not until I get shipment verification from Prusa and I cannot see what failed through the guarding but I will update when I do.
Welcome to the club. If you want to print sooner than the replacement comes and are comfortable wiring mains voltage, you can use a temp replacement. I bought this:
https://www.amazon.com/gp/product/B00KTJE3L4/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1
but I expect a cheaper supply like this would work:
You can just wire them to mains (snip an old three wire power cord), wire the 24v terminals to the Einsy, and then wrap the bottom of the PSU in tape so the mains voltage is not exposed. Use a power-strip with switch as your on/off, and you'll loose power-panic, but you can print.
I've designed/printed a more permanent mount (with switch, power-panic, plug) for the first psu now, so I'm permanently printing with that now. My replacement was also defective (not dead, just dropped voltage whenever the bed heated, resetting the einsy)
I picked up the mean well and got it installed. Everything is working, except the current mount does not fit.
Does anyone have a mounting solution?
Thanks
Re: Power Supply failure
I picked up the mean well and got it installed. Everything is working, except the current mount does not fit.
Does anyone have a mounting solution?
Thanks
Which meanwell?
I have a mount for the MeanWell 350. It's got a solid brace from the upright frame to the rails, and there is a base for the MeanWell 350 that holds the prusa plug/switch/power-panic board.
It's in scad format, so you could modify it for a smaller meanwell if desired.
I've got an earlier version in github, haven't uploaded the latest yet. I will if there is interest.
Re: Power Supply failure
I'm using NES-350-24.
Would love to check out those models!
Re: Power Supply failure
Power supply failure here as well. Printed great the first day. Then it went to preheat and rebooted. Did a factory reset and made it all the way to first layer calibration and rebooted again. Sent a message to support and waiting to hear back.
Interesting, you have "mode 2" of the power supply fail.
Mode 1 is outright failure. Prints fine for a while (a month in my case), then dead. Blown fuse and/or blown supply. 0V out. Several folks have had this one.
Mode 2 is "weak PSU" mode. This happened on my replacement, but I haven't heard others mention it. The PSU outputs 24V and can generally run things just fine. However, it is marginal on the current it is able to supply. When pre-heating the nozzle, I'll see it drop to 20-22V, and when heating the bed it can sometimes drop all the way to zero (or below 5V), low enough to reset the board. Since the board resets, the bed turns off, and the PSU then pops back to 24V again (no load!).
I managed to make it half-way through a print before it reset, so it isn't always immediate.
I'm still waiting for them to ship me my 2nd replacement, it's been a week since I contacted them. Running with a different supply (which is rock solid at 24.1-24.2 V while idle or heating bed and nozzle).
Mode 2 sounds about right. Pretty frustrating experience right now, and not hearing back from support on a $750 kit doesn't help.
I saw your amazon links on better quality power supplies, but I'm not super comfortable with wiring mains so I'm stuck for now.
Re: Power Supply failure
For those that had a power supply go bad, were any of them connected to a UPS?
I happened to have mine connected to a UPS (which my Mac is on). It's not under battery backup, just the surge protection side. I have the flickering lights in the room while the bed is heating (and clicking). I've printed PETG (240C / 90C) for several prints over 4hr each.
Running the printer on A UPS might not be recommended as the AC signal (sine wave) is not the same as it would be on the wall outlet. Some UPSs do weird things to outputs especially when running on battery.
-Eric
Eric Z.
Re: Power Supply failure
Mode 2 sounds about right. Pretty frustrating experience right now, and not hearing back from support on a $750 kit doesn't help.
I saw your amazon links on better quality power supplies, but I'm not super comfortable with wiring mains so I'm stuck for now.
I will work to get the latest up on github. Hopefully tonight, but no guarantees, I'm at an offsite work function.
edit: I just threw them on thingiverse. Let me know if you can get this and if there are any issues.
Re: Power Supply failure
Here's a question for you all. If you move your print head manually (side to side) does your menu screen light up? Is that normal? I know the general mechanics of why. It just isn't something I run into a lot and it has bugged me since i first set up the kit.