Monday 30th July 2012: 3.16pm. Got my second hand #PlayBook today. Typically the thing refuses to boot - at all. What I get is a single red light for about seven seconds, then it flashes yellow five times, then it hard switches off and refuses to notice the power button.
Turns out this is a very common problem - the Playbook refuses to boot if its battery charge is too low. Unfortunately, it also refuses to charge when it's battery is too low because it thinks it doesn't have enough power to turn on enough to start charging, which is extremely unhelpful of it.
Tried hard factory reformat (in fairness, the Blackberry desktop software makes this the most painless I've seen from any mobile vendor, it twigs your device is screwed and offers to hard factory reformat it) - unfortunately too little power to boot after the hard format. Found a guide where basically you repeat turning it on and it crapping out while pushing 10W of power into it until enough enters the battery for it to start the charging cycle. Did that ten times and volia, now it's got a pulsing yellow light which I assume means charging.
Note to self when I start work at RIM: submit bug report that RIM devices must always, always, always try charging when you got AC power, no matter the battery state.