After 1st Print, Motors & Heat are not accessible.

I built a Prusa i3. Arduino 2560 with RepRap Ramps 1.4. & using Windows XP. I load Pronterface ( using Slic3r) & was successful with my 1st print. Now I go back to access the printer & I cannot get the motors to work or the extruder temp. I have rebooted my computer, unplugged USB, etc. & once I hand moved the Y axis to it's Endstop, then the motors were available again. So I made a second print. Now, nomatter what I do , I can not get the motors online or the extruder temp. ??? Help? Anyone? Is COM3 giving me problems?

Ok, seems I was too hasty in asking 4 help..... one of my 12V wires to the ramps was just a little loose... Duh! Now, however, after a print, no heat & no motors again.... all wires are tight. I'm getting power to the two inputs, & get 0 reading on the heater outputs????

Help Please!

Edited 1 time(s). Last edit at 02/23/2013 10:48AM by JacktheKnife47.