[Solved] Help - hotend issue?  

Disassembled and pushed filament into hotend manually, still dosent melt??!

At what temperature?  Try this (with PLA) at 10°C above the print temperature of your hottest printing filament.

Cheerio,

RE: Help - hotend issue?

As stated above, i tried that at 215 C and even tried it at 275 C (PC) while trying to insert PLA that I previously succesfully printed with at 205 C. Tried other PLA filaments too, nothing melted properly.

Filament became goopy and somewhat malluable but did not melt properly.

When I touched the filament to the side of the block it melted normally.

For some reason the filament insert hole thingy dosent seem to take the heat of the block properly it think?

RE: Help - hotend issue?

To add further clarificarion i removed to heat dissipitator when I disassembled it so its the insertion part of the block that isnt heating up properly, which is part of the heating block.

OK, about the only thing I can think of is a layer of overbaked, charred filament - lining and insulating the hole.

It's probably worth contacting Prusa Support via live chat - but I suspect the answer will be 'Buy a replacement hotend.'  Although you could, in theory, machine or burn out the part, in practice this is difficult without specialist tools.

Cheerio,

RE: Help - hotend issue?

I'd change the nozzle and maybe the heaterblock. Even if the latter melts the filament the thread may be corroded on both parts so that the thermal conductivity between them is lower. The block itself is hot but the flux of heat into the nozzle may be less than usual. Maybe it is enough to just clean the thread of the nozzle with a small brass brush. But if you have the nozzle out anyway, I'd just go for a new one. The one I have in my MK3S ist a hard plated brass nozzle. Please choose one of good quality. It does not cost much but it is one of the decisive parts of your printer. I put a tiny wee bit of cupper paste onto this thread. Do not apply any thermal paste to the thread between heaterblock and heatbreak. Increasing the flux of heat into the heatsink would be counterproductive.

Another possible reason might be a damaged cable of the heater cartridge. When some strands of the wire are broken, the current may be just enough to heat the block properly. Measuring the resistance is easy. 

When the cartridge has been in the heaterblock for ages it might be somewhat baked in and stubborn to get out. Please treat the thermistor with care. Changing the heaterblock is no rocket science. If you change heating cardridge or thermistor, routing the cables into the electronic box is somewhat annoying. My old MK3S still has its first set of cartridge and thermistor.

RE: Help - hotend issue?

Thanks for the advice. I already bought a new high quality nozzle because I needed one (I was still using the original one, it lasted crazy long), but that wasn't the issue. 
I will try the methods suggested above and report the results.

I want to avoid changing the entire hot end because its not very economical anymore, at that point I would get more value using it as a donor/selling parts for repair.

RE: Help - hotend issue?

Yup, just the nozzle is the cheap way to try to keep the machine printing.

RE: Help - hotend issue?

So....
Found the issue. Somehow the "Hotend heatbreak" was clogged with material that dosent melt at 275 C, maybe the PTFE tube melt somehow...

I blowtorched the shit out of it until it burned away, then cleaned the soot.

Would recommend 10/10.