Did I short my RAMPS 1.4

I was trying to diagnose why my extruder was not heating up by testing the voltage across the thermistor and D9 and for some reason I got it in my head to test the stepper drivers. I placed the multimeter across a stepper driver on the actual device itself not on the header,this resulted in the hotbed LED shutting off. I disconnected all the PSU and the Arduino immediately. I replugged the Arduino to my computer connected to pronterface and it seemed to work until I turned on the PSU. The printer no longer recognizes the Arduino and I get "usb not recognized"

I'm using an ATX switching Power supply @ 12 V and .8 A.

What I've tried:
-Unplugging all the stepper drivers

When I did this for some reason I smelled a burning. To which I immediately unplugged everything. I felt around the Arduino and RAMPS nothing was remotely hot.

Any idea what I did/how I can fix it?

Post a close up pic of the Arduino - you may have barbecued the voltage regulator

---

_______________________________________
Waitaki 3D Printer

I think you maybe right I'm not sure if you can see in this picture but it looks as if something popped or something. How would I test this?

You can't test that - its destroyed. Replace the chip and see if that cures it - if not, you will only have wasted a few cents but you will need a new Mega.
By the way, to test the thermistor, just unplug it from Ramps and measure the resistance. Also, D9 may be your fan - the hotend is usually D10

---

_______________________________________
Waitaki 3D Printer

Hey sorry about the late late update, had a hard semester; thank you so much! I just finished replacing it. Surface mount components are satans asshole. The short problem is resolved. I am trying to diagnose the hot end now. I did a resistance test on the power cables and got a readout of about 450K ohms is that what I should be seeing?

update: also tested D10 did not work. It did not heat up

final update: I am an idiiot. I thought I just needed to take the two cables labeled PWR+ and plug it in, but I actually needed a PWR+ and PWR-. Then I found out one of my wires do not work, but the hot end is heating which is great

Edited 2 time(s). Last edit at 05/29/2014 03:51AM by ryaric.