Keyboard suddenly not working

[karga]

I have set up my raspberry pi with raspbmc and a keyboard to control it. It was working for a week in the bedroom where i commonly use it, though I noticed that the keyboard never works when I use it in the kitchen on another TV. The problem with the keyboard must be a power issue, because if I draw power from the bedroom (same plug as used normally in the bedroom) and plug the raspberry pi into the TV in the kitchen, the keyboard works just fine.

But now the keyboard doesn't work in the bedroom either. I am suspecting the power supply to not bring enough amps, but I bought a 1.5A to be sure it could deliver the minimum of 700 mA (basic + wifi and keyboard). I haven't yet tested the actual power output of the psu (will do so this weekend), but is it even possible for the psu i bought to degrade that fast?

Just to check, the keyboard doesn't work either if I remove the wifi-unit. The keyboard works just fine on another computer.

[MaxK1]

I don't think anyone ever said 700mA was enough for the Pi, a keyboard AND wifi... As for power supplies "degrading" - a poorly designed supply/charger can degrade VERY suddenly

[karga]

Unfortunately I can't find any real sources, but lots of places mention 500 mA for the rasp and 100 mA for each usb device.. still 1500 mA should do the job though?

[MaxK1]

In theory, yes. But - that does not mean yours actually delivers what it says, 100% of the time. And I suspect that is the source of many of the complaints that it "quits working after a few minutes". If a battery charger doesn't deliver for a few minutes, who cares? As long as the battery charges overnight, that's "good enough" for the intended purpose. The Pi is going to get really bent outta shape with that -
USB devices fail to reset properly to "random" reboots of the Pi itself.