Hot End Wiring

[USMCPelto]

I seem to have issues getting my Hot end to heat up. In Repetier, the bed will turn on, no problem, and the LED comes on the RAMBo...I can home all the axis, move the carriage around, etc. When it comes time to turn the hot end on though, the LED never comes on. Both Thermisters are working and I can tell that the heat bed and hot end are at around 24 degrees C, so they're reading correctly. The Bed's temperature rises when I heat it up, so that works properly too. Any idea why the Hot end won't get hot?

[Polygonhell]

If you turn the fan on, does an LED come on?
If not you've probably blown the fuse for the mosfet circuits.

[USMCPelto]

The Fuse didn't look blown when I took it out, but I'll try to find another one.

Also, when I enable a fan in Repetier, no LED came on either.

[Polygonhell]

The Fuse didn't look blown when I took it out, but I'll try to find another one.

Also, when I enable a fan in Repetier, no LED came on either.

There are 3 fuses, the one I'm referring to Is the tiny 5A ceramic fuse near the top of the board near the power connector, not the large automotive fuse. You'll have to test it with a meter, there is no visual indication it's blown.

[USMCPelto]

So, I'm not exactly sure what I did, but for some reason now, if I turn on the fan (The one that's not there, I don't have one) and the heat bed, then the hot end actually heats up. Not sure what happened or why they both have to be set to on, but it works!

[Polygonhell]

So, I'm not exactly sure what I did, but for some reason now, if I turn on the fan (The one that's not there, I don't have one) and the heat bed, then the hot end actually heats up. Not sure what happened or why they both have to be set to on, but it works!

You probably have a wiring problem then.
There are LED's on all the Mosfet outputs on the RAMBO board, you should be able to see them go on and off when you set temperature, or turn the fan on and off even without the bed or hotend plugged in.
If those work as expected, then I'd start disconnecting things and checking resistance looking for a wiring issue testing each one after you plug it into the board on its own.

[USMCPelto]

A Red light comes on...but not if the fan is turned on exclusively, and not if the Hot end is turned on exlusively. If both are on in Repetier, then it lights and the bed heats.