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Print Core Jammed after filament build up

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Hey guys, 


Unfortunately the fan bracket popped open during a print last week and a good 3 hours worth of filament accumulated and backed up into the print head of my UM3 extended+. This left a fairly significant blob of polywood stuck in and around the print head and extruding nozzle. 


I've cleaned the worst of it away using microshears and files and now there is just some gunk left in some hard to reach and fiddly places at the back of the nozzles where the wires are. Ideally I would like to remove the AA print core to finish up the clean up operation but due to the accident there is now a loose/dirty connection with the print core. Therefore, before I'm able to scroll through the menu to remove the core, I get a max temp error and all menu options disappear and I'm unable to proceed. My only option is to switch off the printer. 


So I'm asking for some advice regarding my next steps and options... Is the only way around this to disassemble the print head? I haven't done this before (although I'm happy to give it a go!) so my worry is that I will spend time disassembling the print head and I still won't be able to get the print core out! I guess this is not the case but I just wanted to check. Any other suggestions/options are also very welcome!


Thanks in advance! 

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do you have an idea what is blocking the core for removal? there is never a need to remove core's via the menu, even in normal operation I switch core's all the time without using menu operations (same for fillament change).


If there's a buildup of material blocking the core you may try adding some heat with a hot air blower, but be carefull not to overdo it with the heat...


Without a picture it's hard to see the severity of your issue, so I have no idea if there's a need to still disassemble the head for cleaning.  Though it's a pita ofc, it's not to difficult  to do, and also the spare parts of the head (besides electronics and the metal bottom) are really cheap, so when in doubt I would replace parts....

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Hi @ultiarjan


Thanks for your reply. Ok so this is good news that I might need to disassemble the print core! 


So I can remove the print cores manually without using the menu simply by pushing the grips together with my fingers? This is also good news. However, I currently cannot do that - they seem to be stuck. I assume this is because of the filament build behind the cores. 


I will add a photo shortly. Sadly there's been a casualty in that one of the print core wires to the Olssen block/nozzle has broken (it was completely encased in filament and had been pushed into an abnormal position).Are these replaceable or will this require the purchase of a new print core? 


Thanks again for your help!  

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