Imac only responds from sleep with power button

[artczar1]

I have a mid-2011 27-in. iMac running OS C El Capitan 10.11.6. It's old, but hasn't gotten much use, and has been problem free until now. I'm using a hardwired Apple keyboard and trackpad.

This past weekend it stopped waking from sleep when using the keyboard or trackpad. The only way to wake it now is to press the power button, and then the background on the login page is a grey color, which I do not recall seeing before.

I reset the SMC, but that didn't change anything. I also tried to reset the PRAM/VRAM, but it doesn't seem to recognize the keyboard and boots as if I'm not pressing any keys on startup.

In Energy Saver, I set the computer to 'never' sleep and un-checked the "put hard disks to sleep when possible" box, but this still didn't fix the situation. Any ideas on what could be causing this issue and how to fix it? Thanks in advance and Happy Holidays to all!

 

[ApfelKuchen]

iMac SMC reset is done by disconnecting the power cord for 15 seconds.

Do the keyboard and trackpad behave normally when the system is awake?

 

[artczar1]

iMac SMC reset is done by disconnecting the power cord for 15 seconds.

Do the keyboard and trackpad behave normally when the system is awake?

Sorry. I've done the SMC reset, but it didn't do anything to resolve the problem. I couldn't do the PRAM reset.

Thanks! The trackpad functions normally, but I have an issue with my wired keyboard where it won't type the letter 'c' and instead the 'c' key is working like a 'command' key. I'm going to get and test another keyboard to fix the typing issue. Both issues started about the same time. Is it possible that a bad keyboard is causing an issue with waking from sleep?
[doublepost=1514409360][/doublepost]Okay. I swapped out the wired keyboard with a wireless one and now the computer is waking with the trackpad, so I guess the wired keyboard was causing the problem. Thanks for all the help!

Happy holidays to all!