A young friend's Macbook pro.
About 3 1/2 years old, all she does is surf, watch movies etc. so not exactly thrashed within an inch of it's life unless it spent all its time on youtube.
First sign of trouble was a no-entry symbol on a grey background at boot, meaning that the boot region of the drive can't be found. A few attempts later and not even the no-entry symbol appeared, although it would chime with the 'Apple sound' when starting.
Initial diagnosis was a failed hard drive. None of the usual tricks, like CMD-R and CMD-S had any effect whatsoever. I pulled the hard drive, popped it in a caddy and had no trouble reading it. Popped a spare HDD in followed by an OSX10.6.3 install DVD.... and waited..... and waited...... and waited. It began reading the DVD, then span it down and then, after 7 or 8 minutes, span it back up again. Eventually a pointer appeared that would move following the trackpad, and then another couple of minutes later there appeared a dialogue box asking for a main language selection. English was pre-selected, clicked OK and nothing happened, dialogue froze. After another few minutes the DVD stopped spinning, and at that point I shut the machine down.
As a 'just in case' I carefully reseated the memory, popped the original drive back in, and it then refused to boot from either the HDD OR the DVD. Eventually had to recover my disc using the credit card trick, jamming the DVD at power on until the superdrive ejected it.
What value a carefully crafted block of aluminium and plastic? Looks great, does nowt.
3 1/2 years doesn't seem very long. In researching possible causes it seems mainboard failure isn't too unusual when these symptoms are seen. Guess I'm lucky the mainboard went in mine in the first few months of life, and here we are 5 years later and it still works (although the battery is misbehaving). Wonder what a mid 2010 Macbook Pro mainboard replacement costs, and whether it's better value than a refurb + landfill with the old one?
Bit horrified to see what *some* are asking for a used MBP on the bay. No way is an early 2009 model of ordinary spec worth £450 - that's madness.