Power Supply failure  

Re: Power Supply failure

Hi, All!

I'm a betting man when it comes to a friendly game of billiards or poker, but not when it comes to printing out a piece of plastic vs burning my house down 😉

I ordered a LRS-350-24 on Amazon. Is there any reason to prefer one over the other?

NES-350-24
LRS-350-24

Thanks,

-Dan

Re: Power Supply failure

I would have loved to use a Noctua, but unfortunately they are too tall by just the teeniest amount lol

I hear you. I bought that Noctua and installed it, but it just barely hits a cap on the board. What a pain.

When I get the chance, I'm just going to flip it around and install the fan on the outside of the case. For now, I'm using the stock loud fan.

Can you tell me what size of Noctua fan replaces the stock MeanWell? I have not ordered my MeanWell yet but I think I am going to pull the trigger. I also think I will just install a Noctua on the outside like you suggested.

Re: Power Supply failure

Hi, All!

I'm a betting man when it comes to a friendly game of billiards or poker, but not when it comes to printing out a piece of plastic vs burning my house down 😉

I ordered a LRS-350-24 on Amazon. Is there any reason to prefer one over the other?

NES-350-24
LRS-350-24

Thanks,

-Dan

I'm in the same mode.

The NES has been reported to work with the Prusa power panic. Has anyone tested the LRS yet? Can anyone tell us anything about the LRS in actual service?

Re: Power Supply failure

The NES has better protection, overload, over voltage and over current than the LRS. Also the holdup time is slightly better. 16ms v 12ms on 115vac.
Also the fan kicks in a t a higher temp. Might not be as noisy.

Re: Power Supply failure

Hi, All!

I'm a betting man when it comes to a friendly game of billiards or poker, but not when it comes to printing out a piece of plastic vs burning my house down 😉

I ordered a LRS-350-24 on Amazon. Is there any reason to prefer one over the other?

NES-350-24
LRS-350-24

Thanks,

-Dan

http://www.meanwell.com/py/newsInfo.aspx?c=2&i=449

NES is older line and will be replaced with LRS.

Re: Power Supply failure

Both are still available from Mouser.
https://www.mouser.com/ProductDetail/MEAN-WELL/NES-350-24?qs=wWxCkh6mprzNWHq%2FOduX9A%3D%3D
https://www.mouser.com/ProductDetail/MEAN-WELL/LRS-350-24?qs=%2fha2pyFadugEqLYLM10DT9zqWRgP0eCtasjRatJu%2fK91dEyTWhw%2fFw%3d%3d

Re: Power Supply failure

It's not very helpful if people start using third party power supplies. It has to hurt PR money-wise with all the PSU replacements otherwise they might not see it as a high priority issue.

Re: Power Supply failure

It's not the hassle of having to replace a PS that concerns me. It is the fact that these supplies are not failing gracefully. It is only a matter of time before one of these catastrophic failures actually starts a fire

Re: Power Supply failure

If Prusa chooses not to acknowledge and divulge an action plan to address smoking power supplies (many of them in fact) after two months of reports then I have no problem sourcing a power supply from somewhere else until its resolved. Surely, after the many posts in these forums regarding the stock power supply and the many replacements, they should be aware of the issue and in my eyes they have simply failed to openly address it beyond sending replacement parts.

Prusa! Safety First, Please!

Re: Power Supply failure

To be honest, i'm not sure if there's just a lot of unintentional fear mongering going on here or what but I ordered a replacement NES-350-24 along with the rest of ya'll. My other printer is a Duplicator i3 with 30 days print time on it, and as you may or may not know those things have a pretty well known issue with power-related failures so that's certainly has me trained and conditioned to be warry of ANY power related issues. I did what it took to fix that printer and i'll do what it takes to fix this printer because they're both great printers worthy of the fix.

I'd rather not worry about it at all instead of convincing myself that it's fine and it won't happen to me so bring it on Meanwell.

Re: Power Supply failure

If Prusa chooses not to acknowledge and divulge an action plan to address smoking power supplies (many of them in fact) after two months of reports then I have no problem sourcing a power supply from somewhere else until its resolved. Surely, after the many posts in these forums regarding the stock power supply and the many replacements, they should be aware of the issue and in my eyes they have simply failed to openly address it beyond sending replacement parts.

Prusa! Safety First, Please!

You're assuming it's as simple as a flaw in all power supplies. You have to look at it from a troubleshooting perspective. You shipped thousands of printers to users who average equal time on it's use. A handful of power supplies burn out, you check the power requirements, design and they all look to spec. That doesn't make it so easy to determine the cause. Could be no issue and as simple as a bad batch of power supplies, they do test all power supplies but could be something out of scope in their testing that needs to be accounted for in the future. Could be a firmware bug, could be user, could be a failure with another component affecting the PSU. Could be a bad power source...lots of possibilities. I know they received some power supplies, sometimes the cause isn't simply obvious or quick to troubleshoot. They're probably still investigating which probably requires involvement from outside parties...takes time. Knowing why something failed and what caused it to failed are two very different things.

Re: Power Supply failure

If I order a Meanwell LRS-350-24, is it a direct replacement for the stock PSU from Prusa (i.e. mounting onto the MK3) or are new/modified mounting brackets required? I would also like to reuse the Power Panic board from the stock PSU on this if possible.

Kind Regards

Re: Power Supply failure

If I order a Meanwell LRS-350-24, is it a direct replacement for the stock PSU from Prusa (i.e. mounting onto the MK3) or are new/modified mounting brackets required? I would also like to reuse the Power Panic board from the stock PSU on this if possible.

Kind Regards

From what I have read, the holes won't line up with the bracket. Someone made a replacement and put it on Github a few pages back, but not sure if itll fit the LRS-350-24. If you're comfortable messing with mains voltage you can reuse the Power Panic PCB as long as there is space in the new bracket you make. I'm getting my Mk3 soon^tm, and I think I'm going to use a Meanwell instead too.

Re: Power Supply failure

You're assuming it's as simple as a flaw in all power supplies.

I haven't made that that assumption. Regardless of what is causing these power supplies to fail (internal or external root cause), the fact is, they are failing, and not simply a handful if you spend time with the [SEARCH] button on the forum.

You have to look at it from a troubleshooting perspective. You shipped thousands of printers to users who average equal time on it's use. A handful of power supplies burn out, you check the power requirements, design and they all look to spec.

Really? a handful? What is a handful exactly? 2? 4? 50? What is an acceptable percentage of critical thermal failures for a product?

That doesn't make it so easy to determine the cause. Could be no issue and as simple as a bad batch of power supplies, they do test all power supplies but could be something out of scope in their testing that needs to be accounted for in the future. Could be a firmware bug, could be user, could be a failure with another component affecting the PSU. Could be a bad power source...lots of possibilities. I know they received some power supplies, sometimes the cause isn't simply obvious or quick to troubleshoot. They're probably still investigating which probably requires involvement from outside parties...takes time. Knowing why something failed and what caused it to failed are two very different things.

There has been zero public communication regarding what they're doing doing (if anything) besides replacement. Are they even investigating at this point? Given that they have failed to acknowledge an issue and respond accordingly over the duration of these forum reports and who knows how many replacements, shouldn't sit well with anyone.

Re: Power Supply failure

There has been zero public communication regarding what they're doing doing (if anything) besides replacement. Are they even investigating at this point? Given that they have failed to acknowledge an issue and respond accordingly over the duration of these forum reports and who knows how many replacements, shouldn't sit well with anyone.

Exactly! I absolutely agree. People seem to underestimate the impact a public statement about this can have. That public statement can be anything - "we are investigating", "we don't consider this an issue", "we don't care". Anything is better than complete silence.

Re: Power Supply failure

Really? a handful? What is a handful exactly? 2? 4? 50? What is an acceptable percentage of critical thermal failures for a product?

Based on this thread, counted the failutes vs estimated units shipped...

There has been zero public communication regarding what they're doing doing (if anything) besides replacement. Are they even investigating at this point? Given that they have failed to acknowledge an issue and respond accordingly over the duration of these forum reports and who knows how many replacements, shouldn't sit well with anyone.

They have asked people to return their bad PSU, that would indicate concern and informed sender they would investigate. Though I agree, a simple post "we are investigating" would make a lot of people feel better rather than waiting until there is a final answer.

Re: Power Supply failure

If I order a Meanwell LRS-350-24, is it a direct replacement for the stock PSU from Prusa (i.e. mounting onto the MK3) or are new/modified mounting brackets required? I would also like to reuse the Power Panic board from the stock PSU on this if possible.

Kind Regards

I have put up an adapter for the NES-350 (search higher in this forum) and somebody else has created an adapter that can be configured to support the NES-350 and the LRS-350 (which I believe is smaller). I don't think he had tried the LRS-350, but was just using Meanwell's specs to size it, so YMMV.

https://www.thingiverse.com/thing:2812350

Re: Power Supply failure

Just picked up a sp 320 24, works perfect. I just kind have it wedged in the original bracket and taped it to the frame for now.

Prusa just shipped me a replacement , im gonna keep the 320 in now. I also ordered a second mk3 , besides the psu issue the printer is amazing.

Re: Power Supply failure

If I order a Meanwell LRS-350-24, is it a direct replacement for the stock PSU from Prusa (i.e. mounting onto the MK3) or are new/modified mounting brackets required? I would also like to reuse the Power Panic board from the stock PSU on this if possible.

Kind Regards

I have put up an adapter for the NES-350 (search higher in this forum) and somebody else has created an adapter that can be configured to support the NES-350 and the LRS-350 (which I believe is smaller). I don't think he had tried the LRS-350, but was just using Meanwell's specs to size it, so YMMV.

https://www.thingiverse.com/thing:2812350

Hey. I'm the author. Someone printed the version for the LRS and confirmed everything lined up. I updated the description to include screws required.

Re: Power Supply failure

Really? a handful? What is a handful exactly? 2? 4? 50? What is an acceptable percentage of critical thermal failures for a product?

If there were 50 failed PSUs for 7799 orders shipped that comes out to 0.6% overall failure rate. That's pretty good if you ask me. There's always going to be defectives with any manufacturered item. A little more than half of a single percent failure is pretty good.