Heatbed unexpectedly stopped heating

Hello everyone,

So I have RAMPS 1.4 , X power Pro 650W computer power supply, and MK1 heat bed. I have printed about 3ish pounds of filament so far and today as I was printing I noticed that the heat bed stopped heating, after some testing I found that if the heat bed is directly connected to power it heats just fine but now if it is connected to my RAMPS board it blows my power supply. After a while the power supply turns on as long as my heat bed is not connected to the RAMPS board.
I am now off to buy a switch and manually turn on and off the heat bed but that's a pain. How and can I fix this problem?
Thank you for any advice.

My Vlog

Bad heated bed MOSFET on RAMPS? Have you tried hooking up the extruder to the HBP terminals and setting the bed temp in pronterface?

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- akhlut

Just remember - Iterate, Iterate, Iterate!

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Hmmm....

OK so more tests

Test One: I bought a switch, directly connected the - to the heat bed and + to the switch to heat bed AND... nothing?

Test Two: Directly connect the power to the heat bed and it started to heat up. At 37Celecous my wire smoked up and melted... I got quite excited and pulled the plug (it's quite stinky) After opening up my window I cut the melted wire off.
Photos of melted wire

Test Three: I switch both terminals (in power to the RAMPS hot end power to heatbed and the out power on RAMPS hot end power to heatbed) and set the bed (now the hot end) to 110Celecous and it started to power up.
???? So my RAMPS is fine????

I wonder if I was trying to use to much power to hotbed and RAMPS didn't like that? and/or my wire selection (22 gage) was not well insulated. Should there be that much heat in the wires?

Edited 1 time(s). Last edit at 04/03/2012 05:37PM by BobFA.

Fixed

I bought some 14 gage wire rated for 15 AMPS and everything works... for now.

So I believe what happened is that the 22 gage wire had to many Amps running though it that eventually the wires melted together. The good thing is that the heat did not kill my RAMPS.