heat bed just stoped working

OMG HELP PLEASE !!!!!

I have no power at heatbed.
I was succesfully printing items for last two days and without warning something went wrong.
My electronic is Sanguinololu 1284p with Marlin firmware.

Power supply is PC power unit giving out 12v @ 15 amps

Printing well and very pleased with my Prusa i2 and then lost power to my heatbed. After hours of testing I found a short in the wire from my electronics and my heatbed which I have now corrected. Tested power from my boaurd and was getting 11.7v reading until I connected the heatbed then power just stopped.

So fault on heatbed.... Got new bed with LEDS already fitted.... No power...
So to test the bed i connected this directly to the 12v power supply and it heats up like a dream.

Also if I set my temp for the bed to 60c in pronterface and click set the bed stays powerless but my hotend heats up until it reatches max temp set in fireware.

Am lost anybody have a clue whats wrong..... I would be most greatful for help....

I read in one of the readme files for the Sanguinololu board that the traces to the heat bed on the board are too small for you to pull any serious power through them without hurting the board. You may have fried a trace. I use a power relay on my repraps, they use the control board to just turn the power to the bed on and off, while the relay draws its juice strait from the ATX power supply. Because of that my control boards don't have to lift as much of the weight.

I have one of these boards but never printed with it. PM me if yours is toast, I can part with mine to replace yours (I use printerboard on my repraps). I can send you a diagram of how to wire up a power relay, and you can get the part at your local auto parts store for 15 dollars.

did you find a solution i have same problem?

Yes I sent back to the place I got it from and asked them to test it for me. They sent me back a report and it turns out the chip was at fault and so it was replaced F.O.C.

If you can get someone who knows what to look for to test it, Its much easyer.

Here is that guide for wiring up a relay. It is for a printerboard, but just substitute whatever board you have where your heat bed connects and it will work the same.

Many thanks Im off to get a replay..

This problem is now sorted so this thread is now dead.
Many thanks to all who helped.