Strange behaviour from a Macbook Pro

Hi, until this morning my macbook pro was fine, nothing strange.

however now, it is as though no charge can get from the battery to the computer. The battery charges fine and the computer works on power. However even with the battery full, if I unplug the computer from the power, after about 10 seconds the computer suffers a power failure (as if you are using it with no battery in and the power is pulled out), sounds exactly like a hard reset you hear the hd head clunk and the pishwt noise(cant believe i just wrote 'pishwt' ). also the macbook will sleep fine and stay sleeping on battery power, but when you wake it from sleep it begins the process (hear the superdrive whirr (no dodgy phonetics this time) and then the power failure again. The same thing happens from a cold start , once got half a second of the chime and all went dead.

anyway this seems very strange behaviour, i have run disk checks and verification, there is nothing in the logs to my knowledge that indicates this. I dont believe this could be a software thing due to the nature of it.
I was using it as normal last night, put it to sleep on the power, woke it up this morning off the power and worked fine. put it to sleep took it to college, opened it up and problem city.

sorry to ramble, but I would appreciate any help anyone could offer.

many thanks,

 

thanks for your replies,

do you have a location of the diagnostics that i could download (a friend had the disk after the genius bar left it in but he is some distance from me at the moment).

resetting the PMU was one of the first things I did after all the usual trouble shooting, then searching on google/forums, then eventually posting here.

it doesnt go into a coma, it is a complete loss of power, if i want to start the computer up again I have to plug the computer into the power and it will boot from cold, even if i had been doing work or comp had been sleeping.

I have had this macbook pro just over a year (just out of warranty, typical) but i have insurance so cost isnt a big issue.

 

I am reluctant to believe that is is just a bayyery issue i use myblaptop on a daily basis on and off the power and frequently fully charge/discharge the battery it currently has done 315 cycles and is at 75% health. The battery holds its charge fine, the lights on the battery correspond with what os x indicates and apart from the obvious problem there are no hardware or software indications that anything is wrong.
75%