My iMac 27in keeps cutting down every time I try to search Internet or just at idol screen please help

Hi,

First, reset the NVRAM. Instructions here > https://support.apple.com/en-us/HT204063

If that doesn't help, reset the SMC. Instructions here > Reset the System Management Controller (SMC) on your Mac - Apple Support

And if the resets to not help, please tell us what resets you did, and if they generated any useful results at all.

But if the problem is continuing, then please post the EtreCheck output

<https://discussions.apple.com/docs/DOC-6174> or <http://etrecheck.com>