Broken RAMPS or Arduino?

I disconnected all wiring to my RAMPS board, removed the RAMPS board and soldered on new pin headers for the servos, AUX-1, AUX-2 and AUX-4. I did some basic sanity checking (checking for shorts and that the conductivity made sense with a multimeter) and put everything back together.

Now I have the following problem:

Reporting endstop status
x_min: open
y_min: open
z_min: open
Can't read from printer (disconnected?) (SerialException): device reports readiness to read but returned no data (device disconnected or multiple access on port?)
Can't write to printer (disconnected?) (SerialException): write failed: [Errno 5] Input/output error
Can't write to printer (disconnected?) (SerialException): write failed: [Errno 5] Input/output error
Can't write to printer (disconnected?) (SerialException): write failed: [Errno 5] Input/output error
Can't write to printer (disconnected?) (SerialException): write failed: [Errno 5] Input/output error
Disconnecting after 4 failed writes.
Disconnected.

The "Can't read from printer" message is printed whenever I activate an endstop.

When this happens, the device disconnected and reconnects to the computer (it appears as a new USB device), I'm assuming the Arduino restarts.

What could cause this? There are no obvious shorts on my soldering. The temperature sensors and stepper motors work fine (X, Y and Z).

I'm using the same firmware as before (initially I flashed to Marlin 1.0.2 but when I got this problem I reflashed to my old 1.0.0 stable version as I initially thought the problem was firmware related).

I've done a more thorough test of my soldering, I've measured everything for any shorts, and there are none.

I've also tested the board with a minimal setup, only the endstops and temperature sensors (which are working and reading good values) connected to the RAMPS and only USB connected to the Arduino. The same error occurs. Every time any endstop is activated, the device disconnects and I get those errors from Pronterface. This happens when activating any of the X, Y and Z endstops.

Most likly your endstops are wired incorrectly, maybe you have them plugged in backwards?

They are just swicthes and should connect S to - it sounds lke you are connecting + to - wich will stop everything. and most times kill the voltage regulator on the mega

Edited 1 time(s). Last edit at 03/20/2015 06:03AM by Dust.

Quote
Dust
Most likly your endstops are wired incorrectly, maybe you have them plugged in backwards?

They are just swicthes and should connect S to - it sounds lke you are connecting + to - wich will stop everything. and most times kill the voltage regulator on the mega

You were right, I don't know how, but somehow I made a huge mistake and connected them to + and -, which obviously is very bad. But it seems to have survived. Thanks.