I've just bought a Dell Streak Mini/5 and charged it using the USB cable. The device switches on, and works fine (I can connect to the internet via wifi, and run all the apps I've tried running), however when the Streak sleeps (either by me pressing the 'Power' button, or by leaving it to time out) when I try and 'wake it up' by pressing the power button, a colourful stripe a few px wide appears down the screen for a short time (less than a sec), and then the backlight stays on, but the screen remains blank.
Does anyone have any ideas? My first instict was a screen issue, but I'm not sure as the phone works fine until I try and make it sleep. I'm tempted to try a firmware update, but I don't want to void my warrenty. I've tried a hard reset.
Thanks in advance.