Hot end comes on full power as soon as Huxly is plugged in.

Hi Guys,

I have got a weird problem with my Huxley that I have had now for about a moth but not had the time to look into it, so the printer has been on the shelf.

I am using Melzi v2 electronics.

When I plug the Huxley into the mains, the heating element (I have both a standard Huxley resistor and a nichrome winding hot end) goes full power. If the power is not cut within 20-30 seconds the hot end element burns out. I am not sure if the first burn out has also damaged the PTFE components on the hot end.

In Pronterface, the temperature sensors all read back the expected results, so I think the problem is with the PWM on the hot-end output, or that the mosfet that switches the hot end has been damaged and is jammed 'on'. I checked it out with a multi-meter and it seems to be OK.

I don't want to have to buy a new controller, and would prefer not to have to change the mosfet if I can.

Has anyone had this before, and is there any other problem that could be causing the symptoms?

Thanks,
- Lars

SOLVED!

See the other thread here:
[forums.reprap.org]

My solution was a bit hacky, but hopefully it will help anyone else who has a similar problem.

I can't edit the title of this thread, if appropriate, can a mod' change the title to solved or merge this with the linked thread?

Cheers all,
- Lars