Man I have NEVER seen this before.
New Heater cartridge, reaches temp in under 3 minutes…Extrusion appears good and fine, no clogging. Tell it to print and 2 minutes in…heating just gives it up. (Fuse? The Printer has those Rumba bad-reputation Polyfuses)
I’m thinking it’s the fuses…do you think it’s the fuses? Man…I sure wish Radioshack were still around. Guess I’ll hit the auto-parts store and see what they have for fuses.
RadioShack is still around. They didn’t close all of their stores.
I think this is one of those 'sit down and breathe kinds of things…Microcenter is near the office, and they’ve got at least as much nifty stuff as Rat Shack ever had. But still…fuses?
Now that I have woken up and think about it - Test the resistance of your new heater cartridge. It could be shorted against the housing and causing it to use way more power than it’s rated for. The problem here might not be the fuse.
Yeah… There are a few radioshacks, I have one probably 8 minutes away, but the one 2 minutes away just closed.
@ThantiK has a good point. If it’s the same wattage as your last that is most likely your issue. Odd thing to see though… I think Microcenter sells heater cartridges as well if I’m not mistaken. If they’re any good I have no idea
Are you sure this is not from Thermal Runaway protection in Marlin.
This was enabled by default in the new RC versions. I think probably from RC 2 onwards…
Polyfuses are not something you can pop out and change they are soldered on the board. They are a kind of self resetting non replaceable fuse. You can short them out if they are causing trouble as repeated resets can wear them out but you need to find out why it’s resetting first. @ThantiK is on the right track here test the resistance across your cartridge wires.
Agreed…and I’m no stranger to desoldering components on boards.
If this problem is repeatable I think it is the small polyfuse (the one that powers the hotend) and it would happen because the power of the cartridge exceeds the maximum current allowed by the the fuse (usually 5A). The fact that you are happy with how fast it is tells us that it is definitely using more power than the one it replaced, so that could tell you why this problem did not happen in the past.
Oh, and it’s still topping out at 237c when requesting 240c which just may be the max capacity of the system.
It does not have to do with the temperature of the hotend but the temperature of the polyfuse, as soon as it gets hot enough it shuts down power.
If you heat it up to a lower temp (120C?) it will need less power and it might stay on all the time.
Shouldn’t be.
Ahh sorry Mike should have guessed you weren’t scared to use an iron 
It was all the talk of Radio Shack threw me, did they ever sell stuff like polyfuses in the ones near you, in the UK (Tandy) they rarely had any small components 
You should be able to find out if it’s the polyfuse by putting a volt meter over it during print. (May be tricky to do practically though.) The voltage should be low during normal conditions. If it suddenly rises (close to rail voltage i assume), the fuse has opened.
@Mike_Miller , are you running Marlin?
I am.
@Daniel_Bull They’d have fuses…NAPA does too, but I thought of Rat Shack first.
Does your LCD screen show Thermal Runaway when the heater stops?
