battery fully recharged but mac not starting up

The three suggestions I gave you should not cause any harm to your computer or data. However it is always best to back up before any type of troubleshooting. Since you can't get your computer to start up at all so far, I don't see how you might be able to back up your files at this point unless you have already done so. There are ways to go about this but they are complex -- for instance trying to install an operating system on an external drive, booting from that external drive to then try to copy (back up) files from your internal drive, assuming that it is accessible. Another way to try to do this is to connect your Mac to another Mac and boot into "target mode" http://osxdaily.com/2010/04/07/how-to-boot-a-mac-in-target-disk-mode/ ... and then your Mac's internal drive shows up like a regular disk on the other Mac. Then you can copy files from your internal drive to the other Mac, e.g. back them up.

As for the three suggestions I gave you in the previous message, I'm actually not sure if I gave them to you in the "best" order. To really know what order to do them in, one would need to know what is wrong with your Mac, which we don't. You could try them in the order I gave you, or in the reverse order (3, 2, 1).

There is one other thing you could try in place of (1) [repair file system with fsck command]. Instead of (1), you could follow the "recovery disk boot" as described here [ http://support.apple.com/kb/HT4718 ] which means you boot the Mac with command-R held down. You should see the option to boot from the recovery disk (instead of your normal disk) and from the recovery disk, you can run Disk Utility. In Disk Utility, you should select your internal drive and select "Repair Disk." This is essentially doing the same thing I suggested in (1) above.

By the way, I forgot to mention that if you proceed with (1) above, after you are done with the "fsck" commands and repairs, the last thing to type in there would be

reboot

which would restart your Mac normally and hopefully boot normally.

Just as an FYI, I have done the SMC reset, reset PRAM, and run Disk Utility (or fsck command) on various different Macs over the past 15 years or so, and none of these procedures have ever caused loss of data. They have fixed various anomalies, including one where the computer wont boot up.

That said, if you're not familiar with or comfortable with the steps you need to follow for these, perhaps you would be better off bringing in your Mac for service somewhere authorized. When you are there, however, you can ask the service provider about whether they plan to try these three things and why or why not.

The SMC reset is to try to reset back to nominal your computer's charging and power management, since you had an anomaly that involved those systems.

The reset of PRAM sometimes fixes situations when a computer seems to forget where it should be booting from. Your computer seems to be having trouble finding a bootable system.

The use of Disk Utility and/or fsck is to repair file catalog errors that might have been induced by your disorderly shutdown (running completely out of power) -- those types of errors will prevent a Mac from starting up if the file system errors involve system files needed fr bootig up.

I THINK that the only way you will lose data from this laptop would be in the unlikely case that your internal hard drive has somehow suffered some sort of major hardware damage (such as the head coming down onto the platters, or material flaking off the platters).

I think the most common reason for a computer not booting is that the startup files have been corrupted by a disorderly shutdown. The "fsck" or Disk Utility suggestions I gave you try to repair that (if that is found). If your computer has suffered some sort of major hardware problem (I would not expect that from simply running out of power, but it is possible), such as the logic board failed, then the last resorts for accessing your data on that laptop drive are:

(1) Boot the laptop into "target mode" connected to your iMac with the proper cable -- I provided a link on how to do that earlier and Apple has instructions for target mode as well. That would mount your laptop drive to look like an external disk to the iMac and you could just copy the files off.

(2) If the laptop won't even boot into target mode, you have another "last resort" to get your files if your laptop cannot be repaired (or if it would be too costly to do so). That would be to have someone remove the drive from the laptop and put it into an enclosure that you then connect to your iMac and just copy the files off to somewhere safe. You will need a technician who is Apple qualified to do this. This is a commonly done however, many people do it themselves if they have the right tools.

I am hopeful that one of the three simple corrective actions mentioned earlier will get your computer booting back up. In the future (hindsight is 20-20), you should purchase a cheap external drive and do regular backups, such as with Time Machine or SuperDuper.

You can try to get AppleCare to help you with the laptop even though your policy is for the iMac, but they probably won't like that, and also the troubleshooting procedures will be different for the SMC reset for those two computers.

.. you should always have abackup of your hard disk and user files. A simple approach is to get Apple Time Capsule and use Time Machine. Another approach is to buy an inexpensive external disk for about $125 and use Carbon Copy Cloner.