I've not used my PSP for ages and thought i'd had a play on it tonight. As luck would have it, i've plugged it in to charge, switched it on and downloaded the latest update but the battery was too low to install it. I cancelled the install but pressing pressing 'ok' and the PSP has gone off and now wont come back on. It's still plugged in at the mains but the 'charge' light isn't on. I've changed the fuse in the plug, faffed with the PSP battery and nothing seems to work. Anybody any ideas??