heat bed power out connector melts down on my MK3
Greetings everyone
I started a certain print and then noticed a powerful smell followed by smoke coming out from the Logic board box. I shutdown the printer right away and upon examining what happened found that the plastic walls surrounding the power out connector positive line have melted down. As you can see in the photos damage is considerable. the weird thing is that the printer was running fine and heat bed fuse is still ok.
For now I just used a file to remove the molten plastic from cable connector and board and printer is back to printing just fine.
However, what do you suggest to prevent this from happening again.
RE: heat bed power out connector melts down on my MK3
The parts heat up when you dont have a good connection between the terminal and the board. So if the connector works loose over time it causes more heat and you get what you had. You have to periodically check that all the electrical connections are tight.
RE: heat bed power out connector melts down on my MK3
@neophyl
Thanks for replying
What you say makes a lot of sense. but why didn't the fuse blow to protect the parts?
RE: heat bed power out connector melts down on my MK3
A fuse protects why blowing when the current goes too much. You had a dodgy connection, that is converting the current to heat at the connector. If the current doesn't exceed the fuse rating then the fuse wont blow.
Think about it this way, your extruder and bed can turn X amount of electricity to heat with the fitted fuse. That same amount of electricity can turn to heat in other places when your wiring/connectors aren't secure.
RE: heat bed power out connector melts down on my MK3
@neophyl
If I understand correctly you mean that as same current has to go through smaller cross section due to loose connection it will cause more heat generation due to higher resistance by a smaller section?
RE: heat bed power out connector melts down on my MK3
@neophyl
If I understand correctly you mean that as same current has to go through smaller cross section due to loose connection it will cause more heat generation due to higher resistance by a smaller section?
That's exactly it. 👍
Also, a fuse is never there to protect parts in any application whether it be in a car, a printer or a house. They are there to stop wiring fires.