When the local tip was bounteous with its dumped Sky+ boxes, bikes parts and so on, they were easy to reset and sell on.
After quite a drought that even had the staff scratching their heads, I picked up a HD box yesterday.
A few googles on the model got me the hard reset key presses and after about an hour of faffing I have access to my own Sky subscription channels and the free to air HD channels.
So, if you see one of these at the tip and you are allowed to get it, heres a few googled tips:
Switch the box off at the mains.
Hold down the left and right buttons on the box (not the remote ) as you switch on again at the mains for at least a minute
When the blue circle recording light comes on, release the left and right buttons and press Select on the box.
The blue light circle should rotate in reverse.
After several minutes the box will be left in standby.
Reboot after a further 3 minutes.
"power reset" - switch off at mains, wait 30 seconds or so and switch back on
"Sky+ planner rebuild" - "Services" "0" "0" "1" "Select" takes you to the "hidden installers menus" - then under "rebuild" press "down" and then "Select"
Third - try a forced software download - Switch off at mains, press and hold down "backup" button on the box and switch back on at mains, continue holding down "backup" button until you see either onscreen message or four leds light up on box front, go and make a cuppa download can take up to 15 minutes.
Btw, if you want a standard Sky+ box, I have a few available.