iMac tripping breaker just by plugging it to electricity!

iMac 21” (EMC: 2638)

The iMac was connected to a UPS but through an extension cable, so not directly.

So the iMac was running as usual when suddenly it went off, with all the other devices that are connected to the UPS. And I have no electricity in the room, the electricity breaker tripped, and the UPS is making that loud beep.

After unplugging everything from UPS, and turning back electricity and etc... I found out that it was caused by the iMac.

(UPS and all other devices are working fine now without the iMac there).

I try to plug the iMac to a different socket, but it immediately trips the breaker even before clicking the power button, just by plugging the cable to the socket, trips breaker!!

I tried different sockets in different rooms that are connected to a different electricity breaker, but the same thing happen.

I tried a different cable, but same thing happen.

I unplugged cable from the back of the iMac and tried the 10-sec hold power button thing, but didn’t help, same thing happened.

TL;DR - iMac is tripping breaker just by plugging it to electricity, without even pushing the power button!!!

Any one has any idea what happened here??

the closest Apple service center is hours far from me and I would really want to try everything before going there.

Thank you!