My Note 2 won't boot up after clearing cache. What do I do now?

[serisu]

I'm trying to get an older Note 2 phone to boot up after taking it out of a drawer to use again. It worked fine before I put it away and it has been a few months. When I first took it out, it wasn't doing anything so I left it to charge overnight. Then when I pressed the power button, it would show a gray battery. So I read some stuff online and decided to try using recovery mode to clear the cache. Now, the phone won't do anything at all. I tried using another battery from someone else's Note 2, but the phone still didn't respond. Is there anything I can do now?

 

[B. Diddy]

Welcome to Android Central! Did you try pressing and holding the Power button for at least 10-15 seconds?

 

[serisu]

Thank you for the welcome.

I have tried that! I just tried it again to be sure. There is no response from the phone, no lights or anything.

 

[B. Diddy]

Assuming your friend's battery was already charged up to full, then I'd suspect either a problem with the phone's Power button or the motherboard.