macbook pro doesn't turn on with power key

Thanks for your reply HWTech, these are all good suggestions but they haven't solved my issue. I ran diagnostics and it said there were no issues, ref code ADP000. Another weird behavior that sometimes happens is that when I shut it down but leave it plugged in, a lot of times when I come back to the computer it is hot, even long after it should have finished charging (as in, I leave it overnight but then in the morning I touch it and it's hot). I can basically only turn it on now by holding the shift/option/control/power keys for 15-30 seconds, and sometimes even that doesn't work until I've tried it repeatedly for 10 or 20 minutes. Like I said before sometimes the fan starts whirring instead of the computer actually turning on. Any more ideas?

Once the computer is on it runs basically okay, nothing out of the ordinary anyways. And there is almost no such thing as sleep mode anymore--basically if it's on and I don't use it for a minute it puts itself to sleep like normal, and it'll wake back up just fine within the next 10 minutes or so. But if it's asleep for a long period of time (not sure exactly what the cutoff is, but definitely after a few hours) then it shuts itself down while in sleep mode and getting it to turn back on is the hard part that I described in the original post. I know this too because once it comes back on I get an error message saying it shut down unexpectedly and gives me the option to send the error report (which I do).

I've done a couple updates and installed a couple programs in the last several months but I'm pretty careful about what I download, I suppose that's a possibility but I think a remote one. I tried booting in recovery mode, but the thing is once it turns on there really isn't any issue to test for, so recovery mode worked fine but when you shut it down the issue comes back. I agree that I think it's a hardware issue, I've managed to contact an authorized mac service place (I'm not in the U.S.) so I will probably just take it in. Maybe I'll try recovery with a time machine backup but the malfunctioning keyboard letter "n" is driving me uts as well so might as well just take it in. Thanks for your time and suggestions, I do appreciate your help.

Once the computer is on it runs basically okay, nothing out of the ordinary anyways. And there is almost no such thing as sleep mode anymore--basically if it's on and I don't use it for a minute it puts itself to sleep like normal, and it'll wake back up just fine within the next 10 minutes or so. But if it's asleep for a long period of time (not sure exactly what the cutoff is, but definitely after a few hours) then it shuts itself down while in sleep mode and getting it to turn back on is the hard part that I described in the original post. I know this too because once it comes back on I get an error message saying it shut down unexpectedly and gives me the option to send the error report (which I do).

I've done a couple updates and installed a couple programs in the last several months but I'm pretty careful about what I download, I suppose that's a possibility but I think a remote one. I tried booting in recovery mode, but the thing is once it turns on there really isn't any issue to test for, so recovery mode worked fine but when you shut it down the issue comes back. I agree that I think it's a hardware issue, I've managed to contact an authorized mac service place (I'm not in the U.S.) so I will probably just take it in. Maybe I'll try recovery with a time machine backup but the malfunctioning keyboard letter "n" is driving me uts as well so might as well just take it in. Thanks for your time and suggestions, I do appreciate your help.