Ramps 1.4 not powering extruder or motors

Hello,
I have a reprap prusa i3 rework. Connected to my ramps 1.4 shield is an Arduino mega 2560. I run it with marlin and pronterface. The problem is when I use pronterface my ramps have stopped working. The only thing that works is the powering of the heatbed, unlike the stepper motors and the extruder that doesn't get any power. I took away all the connected motors form the shield expect one. Then I tested to switch out the stepper motor driver with a spare part, but that didn't help at all. I have voltage into the shield and there are signs on the shield that it would have burned. I have also tried using another Arduino mega 2560 with no success. Does anyone know what might be wrong?

Thanks,
Axel

The ramps has two power inputs

the 5A and the 11A inputs

the 11A is the heated bed. Wich is working fine.

so it sounds like you have a issue with the 5A circuit.

Check voltage is getting through the smaller of the two yellow square polyfuses.

Thanks for your answer. It seems to have 0 V on both sides of the small yellow polyfuse when measuring against ground. The bigger on the other hand has briefly over 12 v on both sides. So the ramps must be broken somewhere before the polyfuse?

I found it. The green power connector had a loose connection.

You're the man with this tip, it was misery for weeks because I couldn't get some of my motors to work all because of a faulty 5V connection, thanks.

Quote
Dust
The ramps has two power inputs

the 5A and the 11A inputs

the 11A is the heated bed. Wich is working fine.

so it sounds like you have a issue with the 5A circuit.

Check voltage is getting through the smaller of the two yellow square polyfuses.