Z87 Extreme4 motheboard does not boot

Dear all, I am in need of urgent help as the desktop contains all my precious file and hardware set up for my hobby. Here is the story in brief. The computer went into sleep and then wouldn't wake up. Tried everything but no luck, didn't use the RESET button (my stupidity). So, I opened the cabinet, removed the CMOS battery, cleared the CMOS by switching the jumper and lettting it remain unpowered for 4 hours. After that, the motherboard seems comepletely dead, no response whatsoever except the fan comes up but no POST, no BIOS LED and nothing.

I reseated the RAM, BIOS chips, switched the BIOS by jumper from A to B, nothing doing, it is still completely unresponsive.

Anyone with expert knowledge, please help, it has taken away my full weekend and would want this machine UP ASAP please.

Thanks you for your support.urgent help

Thank you, I will buy a PSU and try. What is the likelihood a PSU going bad all on a sudden? Right now, the motherboard is on its own, every peripheral disconnected, only one monitor connected and mouse/keyboard through the two USB ports. I can only think, if its not PSU, then the MB is gone for good, but surprisingly, it happened just like that!

Thank you for the help. Changing the PSU helped. Frankly, I was very skeptical about the PSU going bad as it is a sturdy Corsair 500W PSU, very heavy and looks real good and didn't think it can go bad. So I bought a chippy A$39 PSU to see if the PC works and it did. So, I left it in there and run it for some time or as long as it runs.

Thank you once again, really appreciate your help. Stay well and stay safe.