After upgrading my gpu and PC case, computer doesn't wake up from sleep mode / pc doesn't even turn on.

[samiur]

Hello

I've changed my pc case and after replacing my case i saw the case's power button doesn't work so i swapped it with reset button. And i also upgraded my gpu . But now a new problem emerged , if i keep my system under sleep mode for longer , it doesn't turn on / doesn't wake up from sleep mode. Mouse keyboard light doesn't come up and blue power Led lights up but cpu gpu fan doesn't spin until i long press the reset button or cut the power and start it again. 

how to fix it kindly help.

[Needfuldoer]

[ Moved to Troubleshooting ]