'09 MacBook won't start

My wife's 2009 Macbook pro suddenly won't engage. When you push the start button up , the apple logo appears then the little wheel start to spin, then it instantly shuts down. Tried safe boot start up - no good. Try re-installing OS disks, same result .Won't connect to disk, just switched off. OS disk is in drive & won't come out. Tried holding shift key on start up to eject disk, won't eject disk either.
Anyone got any ideas what problem is ? would welcome any suggestions to try. Thanks

Macbook Pro won't start up correctly

Tried resetting the SMC , no result. Tried holding various keys on start up , e.g., shift-option-command; Option-R.; cmmd-s , etc. Nothing seems to work. When I tried CMMD-R it started up with the 4 alternatives. One was to re-install new copy of OSX , but I wasn't sure if the re-instal would keep or delete all existing files, folders, apps, photo etc. Can anyone advise me whether if I proceed to re-instal NEW copy of OSX whether it will delete all old work or retain same. Appreciate any assistance, thanks.

Before you do ANYTHING else, the first question to ask is do you have a backup of what's on the drive?

Hi Chas_m, Most of it was backed up over 3 weeks ago but after that time she hasn't backed it up. That's why I am asking if I go ahead & instal new OSX from prompt which appeared when I started with OPTION-R, is it only re-installing an new OSX & retaining all files ,etc. or will it do a complete re-instal & delete all past files, photos ,etc. ?? It does tell you. Any idea ?? Thanks

It must be at least Lion since Command+R brings up that install menu.

I am pretty sure it will not erase anything and just put in a new install of the version of OSX you have.

I normally do not use Command+R so hope someone else chimes in just in case.

Ref: Macbook Pro won't start

Thanks for the reply Dennis. End up taking it to the Apple store here in Adelaide. The very knowledgeable Genius Bar Tech diagnosed the laptop & stated the battery was running at less than 80 % & anything under 80 % can create similar problems. He stated that if you don't use it as a portable & keep it plugged to power , it won't be a problem, but if you use it as a remote portable away from its power source, the battery needs replacing. As my wife only uses it as a desktop , we decided to not replace the battery & should we take it away on holidays or interstate , we will take the power cord along. Also , as trying to start it on battery only upset the hard-drive & it was necessary to re-instal a new copy of OSX. For your info, in doing so , all past 3 week's work, files, iPhotos & apps were lost. Wifey not happy but only lost last 3 weeks entries, work,etc.,, but happy to have it working again. Luckily, she backed up 3 weeks ago & saved the majority on external hard-drive.
Many thanks to you & others for your input...Sabusforms.