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Be careful with the Prusa Power Supplies Everybody!  

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Buildabore
(@buildabore)
New Member
Be careful with the Prusa Power Supplies Everybody!

I had a power supply failure, so I looked inside the cage. This could have burned my house down. Fuses were fine. Only indication was that the hotbed no longer heated and caused a fault. I spoke with chat support, and was told that I shouldn't have opened the cage after the failure and to just buy a new one. Refused to let me speak to any higher levels and said that they may get back to me later on. Kept telling me that the printer was safe and reliable and this wasn't an issue that happened to their printers. I literally sent him the pictures and he just kept saying No, our printers and safe and loved. Apparently manufacturing defects are not heard of in Prusa land. Kinda irked about it because usually their support is really good. Annoying that almost catching fire apparently isn't a serious enough issue to warrant looking at. :/

Charred connector (cable was red originally)

Charred and melted terminal on PSU

View in the PSU Cage

Posted : 29/12/2022 7:17 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Be careful with the Prusa Power Supplies Everybody!

how old is that printer?    it's got a silver power supply? I thought modern ones are Black!
Was that Screw Loose?
Have you checked the power supply for output? 

Have you considered replacing the wire and trying the printer again?? 

regards Joan

 

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 29/12/2022 7:40 pm
Crab
 Crab
(@crab)
Reputable Member
RE:

By looking at the first picture, it almost looks like they didn’t crimp the red wire connectors.. Maybe something that got missed in the assembly of the wires.. I hate crimps because if they aren’t made well, they fail this way. If a gas tight seal isn’t made by using the proper crimper for a certain fork connector, then over time oxygen & moisture gets in (if its not gas tight) and you get a layer of oxide. This is now a resistance. Heat is current * resistance so the connector now gets hot. The hotter it gets, the more oxide forms.. the more resistance, until a failure you see. I’d check those red connectors to see if they were, in fact crimped.. if not Prusa owes you a Power Supply. It looks pretty conclusive that the failure is that red connector where the crimp was made improperly. I can’t think of another cause .. so I would think Prusa should go good for the PSU. That would be good customer service. This doesn’t look like a PSU failure.. but a PSU failure that was caused by extreme heat by the failed crimp.

Posted : 29/12/2022 9:35 pm
Štěpán liked
jsw
 jsw
(@jsw)
Famed Member
RE: Be careful with the Prusa Power Supplies Everybody!

Yeah, looks like a corroded (possibly wet from environment) crimp lug connector.

The power supply itself is quite possibly OK.  Corroded connections have resistance, which tends to increase as time progresses, and in low-voltage circuits can get very hot.

Posted : 29/12/2022 11:48 pm
Zappes and Štěpán liked
BurningTreeCorpse
(@burningtreecorpse)
Active Member
RE: Be careful with the Prusa Power Supplies Everybody!

I can see how that is frustrating for sure. I think I'm going to add a PSU check to my monthly einsy wire checks I do. I never thought there could be an issue there.

Posted : 30/12/2022 12:44 am
jsw
 jsw
(@jsw)
Famed Member
RE: Be careful with the Prusa Power Supplies Everybody!

Note to myself: Tighten all power supply terminal strip screws and heat bed screws when I take the machine down for maintenance sometime in the next month or so.

Posted by: @burningtreecorpse

I can see how that is frustrating for sure. I think I'm going to add a PSU check to my monthly einsy wire checks I do. I never thought there could be an issue there.

 

Posted : 30/12/2022 12:51 am
Ron S
(@ron-s-2)
New Member
RE: Be careful with the Prusa Power Supplies Everybody!

I put dielectric compound on all my high amperage connections. Never hurts.

Posted : 08/02/2024 12:33 am
r0berts liked
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