Noob problems

So I finally got my Prusa i3 all put together and sort of working.
This morning I finally realized how to turn on the heat in Repetier and when I clicked the icons
the heated plate and hot end got really hot - really fast. Steam under the glass within seconds and what looked like steam or smoke from the hotend.

Now both the hot bed and hot end are very very slow at heating up. Almost 15 minutes in and temp is only 94 C on the hot end and 36 C on the plate.

Folger tech build Rev B.

Replacement parts in order?

CHEERS

Could be slow heating because of different reasons, try something like:
- check with a multimeter if the power supply has low voltage when both heaters are on,
- measure the resistance of the heated bed and heater resistor at the terminals
- review the pwm/pid settings in firmware
Good luck!

Thanks. I will give all 3 a try after work is out of the way.

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Bublgum
the heated plate and hot end got really hot - really fast. Steam under the glass within seconds and what looked like steam or smoke from the hotend.

Now both the hot bed and hot end are very very slow at heating up. Almost 15 minutes in and temp is only 94 C on the hot end and 36 C on the plate.

I don't think that was steam. Maybe a little bit of smoking when you turn it on for the first time as any residue during the manufacturing process might cook off. Or if your filament has absorbed some moisture... But if you noticed "steam" or smoke within seconds then I'd venture a guess that some magic smoke was released. Checking resistance (with things off) and voltage (with things on) will help trace down what might have gave up.

I tested the thermistor on the hot end by removing it and applying direct heat with a heat gun - at a distace. I got a constant (what seemed accurate) temperature increase in the software.
I tested resistance at the terminals for the hot end and got 0. Like I said, im a noob. I tested main voltage off the power supply with both heaters on and got 11.9v constant.

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Bublgum
I tested resistance at the terminals for the hot end and got 0.

Sounds like your hot end served as a fuse and released it's magic smoke.

Yep.
I just wish I knew how to confirm this.

How doe's one prevent this from happening all over again?

CHEERS

You'll have to figure out why it drew too much current. When you get a replacement heater, measure it's resistance to make sure it's within spec. If it's a 12V 30 watt cartridge heater, you'd expect the resistance to be E^2/P = R or 12^2 / 30 = 4.8 ohms. If it's significantly different, then you have the wrong voltage heater or quality control sucks.

Also make sure it wasn't shorted out allowing too much current to flow through it.

I just did a quick test of switching the motor wires from my x axis to the extruder motor with hopes that the extruder motor on the hotend would work... and it does what it should.
Thie rules out the motor being fried I assume. Would the hotend block part have electronics in it that would have failed?? Otherwise I think it's my ramps board.

Thoughts?

Thanks for the help all