The title says it all. I bought this Pi from Amazon about 2 weeks ago and, after I shut it down, it refused to boot. I've tried reflashing the SD with wheezy, to no avail. I have a Pi hub. I tried using the power from that, but it still would not start. When I plug in the power, the red light comes on, the act light is VERY dimly lit, and nothing else. My monitor (HDMI->DVI) recognizes that there is a signal, but shows only black. PLEASE HELP ME. I was dancing when I first booted up my Pi. I am a man.
Seems your wall wart 5V 1.9A power supply may have died and voltage or current output is low?
Try an alternate source? Plug into usb port on PC?
If the RPi on board voltage regulator is faulty (To prove you use multimeter to check 5V rail and 3.3V) you can replace components
You could possibly power it via the IDC header and bypass the DMG2305UX P-Channel MOSFET which may have partially died?