Windows 7: Asus laptop won't turn on

I have an ASUS G73JH, windows 7 64bit home premium. Short version: When I hit the power button, the lights come on for a split second, but then stop, and nothing happens. It won't turn on at all.

I've tried taking out the battery, hitting the reset button with a straightened paper clip, holding the power button for 30 seconds before trying to turn it on without the battery, and every combination. Local computer shop never found a hardware issue. Whenever I turned it into them, they would set it on their shelf and call me the next day, "well, it's working fine now, and we didn't really do anything." Then I'd try to turn it on the next morning, and it wouldn't work. Rinse, repeat several times. They claim to have taken it all apart and didn't find anything physically wrong.

When it was in a good mood, and turned finally on, I FIXED IT FOR 2 MONTHS. I got some advice that the problem happened when it went into sleep/hibernate, that the memory file was somehow corrupted. In other words, software problem, not hardware. I changed the settings to that it would NEVER EVER go to sleep, I disabled ALL updates, etc, and it worked beautifully. Until the other night when, for no discernible reason, the exact same thing is happening again. Only now, it's been dead for 4 days with no miracle wake-up.

Any help would be very, very welcome; thanks in advance.

Have you tried removing the battery and just plugging in the AC adapter ? Do any lights come on ? Fan spinning sounds ?

My advice never have laptops set for a sleep mode. Battery runs low they should shut down or be turned off, I've heard of too many fried mobo's and corruptions with sleep modes !

How many ram modules do you have installed, try removing and re-seating them or go with one module at a time to see if it boots.

Yes, I've tried all combinations of battery/ac, and the same thing happens each time. The power lights come on for a brief moment, then blackness. No fans or sounds at all.

I did try taking out the ram and trying to turn it on, yes, then trying again once they were back. I only tried once, though, and I didn't do one at a time. I can try again.

I would as with desktops a bad or failing ram module will cause boot issues for sure. It's worth ruling out! Also check to see if they're a matched pair of modules?

Try this: Remove the hard disk drive. See if it starts up and runs without turning off, and that you can get into the BIOS/UEFI settings.

Seems like a BIOS problem. I would suggest using TVeblen's method. Try to use the HDD in another computer. Does the computer turn on? If it does,You could also try using the motherboard in another computer and run memtest86 and using SFC /SCANNOW command and also CHKDSK (if it boots). Also run antivirus to see if there are infected files on it. Try to see if there are some loose connections.

I took out the ram and the two HDs that I could see. The machine has three, two 1/4 TB and one 1/2 TB. It didn't help. Unfortunately, I don't feel comfortable taking the entire cover off and poking around, and I don't have any other computers lying around that I can use to "plug and play" the removable components with.

No, it won't go into BIOS/UEFI settings without RAM.
Try installing just one stick of RAM, no hard drives.

ASUS G73JH specs say 2 hard drives. Why do you think you have 3? (and invisible too!)