M201 heatbed failure

[mark2]

Hi all,
I was using my printer at the weekend, and after doing a bit of housekeeping (purging the hot-end after trying to print some laywoo - long, sad story...) I found the heat-bed no longer worked.

I think I might have heard a 'pop' at one point, but there was no burning smell or puff of smoke, so I didn't think much of it, but then I noted the heat bed wouldn't get warm.

Measured the resistance of the heat bed at ~3.6 ohms, does this sound right?

I assume the mosfet has gone, although I can't see any damage on it, or any burn marks on the board or anything. Is there a way I can check it? when turning the heat bed on in repetier I don't hear the expected fan speed increase, which give someone a clue.

Also if it is the mosfet can I swap it for one of the others on the board? as far as I can see there are 4 mosfets but only the two end ones are connected. If they are all the same I would be happy to swap it round.

Thanks in advance
Mark

[Toy]

You can check the mosfet as the post:
http://www.geeetech.com/forum/viewtopic ... 19&t=17039
Yes the mosfets are all the same and you can change them.

[mark2]

Thanks Toy for pointing me to that post, guess I should have had a better search myself before asking, but I find searching in this forum a little tricky.

Anyway, with the help of this I was able to figure out it wasn't the mosfet at all, turned out to be the plugin connector itself. Swapped it with the neighbouring one and it's been fine ever since.

Strangest thing....