luke.m4
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Heatbed connector replaced, worked for 30 mins

Mar 16, 2019 10:44 am

Hi,

I had a heatbed error last week, and upon investigation, the molex clip had melted. I bought a replacement clip and this brought the heated bed back to life with testing manually raising the temperature.

I've just gone to print today and its stopped working again. Theres no LED again and the molex connector is intact. I've checked the wires and they all seem in good condition. Also replaced the molex again. Not sure where else to check and after some advice on where to go with it next.

Luke

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joan.t
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Re: Heatbed connector replaced, worked for 30 mins

Mar 16, 2019 11:11 am

Hi Luke,

have you checked voltages and fuses?
Joan
I try to make suggestions that I believe to be well founded and safe,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.

luke.m4
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Re: Heatbed connector replaced, worked for 30 mins

Mar 16, 2019 12:27 pm

I didn't think of fuses. I'll check those when I get home.

I also dont own a voltmeter, so I cant check voltages.

I've also stuck a heat gun on the heatbed and the temp is rising, which is a good sign. As another note, I've noticed that the red light still flashes on the Rambo when it's trying to raise temp, just doesn't seem to be communicating down to the bed.

***Update***

Fuses are fine.

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PJR
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Re: Heatbed connector replaced, worked for 30 mins

Mar 16, 2019 6:34 pm

If your plug has melted, then it's highly likely that the socket is also badly damaged.

Best solution is to solder tails to the underside of the board and use 32Amp connectors to connect decent new silicon-sheathed cables to the bed.

There are plenty of posts here how to do it.

Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss.

luke.m4
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Re: Heatbed connector replaced, worked for 30 mins

Mar 17, 2019 9:15 am

Damn, I was hoping that wouldn't be the case. If it started working, I wouldnt even have thought about the socket being damaged.

Annoyingly, I dont even own a soldering iron since the "cheap" ones I've owned in the past were terrible, and didn't do enough electronics work to warrant owning a decent one..

Is this the only choice now? I'm surprised Prusa haven't come up with an official solution, since it seems this fault is pretty common. Or is the soldering their official response to the problems?

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PJR
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Re: Heatbed connector replaced, worked for 30 mins

Mar 17, 2019 10:00 am

luke.m4 wrote:
Mar 17, 2019 9:15 am
Is this the only choice now? I'm surprised Prusa haven't come up with an official solution, since it seems this fault is pretty common. Or is the soldering their official response to the problems?
No, it's not the only option, but soldering (in my opinion) has always been the best option on a 12V system.

Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss.

luke.m4
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Re: Heatbed connector replaced, worked for 30 mins

Mar 17, 2019 8:23 pm

PJR wrote:
Mar 17, 2019 10:00 am

No, it's not the only option, but soldering (in my opinion) has always been the best option on a 12V system.

Peter
I'm assuming the other options are a new Rambo or upgrade to the MK3s?

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PJR
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Re: Heatbed connector replaced, worked for 30 mins

Mar 17, 2019 9:03 pm

luke.m4 wrote:
Mar 17, 2019 8:23 pm
I'm assuming the other options are a new Rambo or upgrade to the MK3s?
That's about it :(

This issue used to be blamed on poor assembly. But it also happened to me on one of my Mk2 printers and I know that was assembled correctly. The first failure was the cable (due to flexing) and then, a few months later the connector itself.

I believe that the connectors are "only" rated for 16 Amps, which (in theory) is sufficient and includes a small overhead. But reality does not always reflect the theory too well ;)

Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss.

luke.m4
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Re: Heatbed connector replaced, worked for 30 mins

Mar 20, 2019 3:52 pm

Ok, after contacting support, it is an issue when using higher temps. Its addressed in MK3s but confirmed soldering, replacement connector or new Rambo is the way to go. After linking me to a page that I am "not authorized to access", soldering seem the best way to go.

Is there an idiots guide on what to do/buy in order to achieve this? I'm a complete novice when it comes to electrics and havnt had much luck so far with the search function.

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