[SOLVED] I think I fried my RAM slots while upgrading

[Deftie]

Hey folks,
I have an i5 7600K CPU which was paired with 16GB of DDR4-2400MHz (from Corsair). My motherboard is a Gigabyte Z270, but I'm unsure which one.
I've decided to slap 16GB more, same specs but from ASUS. The system failed to read the new RAM so I removed the motherboard to make sure everything was seated correctly, put it back in and still nothing. Then that's where I believe I ffed up.
I removed the old RAM sticks completely and placed the new one in their slots to attempt to boot based on only those. My system fans work, but everything else is dead.
I tried resetting the BIOS with both the battery and the reset jumper method, nothing.
Is there any chance of saving my system without the need for new hardware?

Edit: Installing the old RAM sticks as they were before doesn't change anything, still dead...

 

[helpstar]

The motherboard´s model number is printed on the board, right above the upper PCIe port.

Did you connect the power supply completely? ATX12V 8pin plug connected as well?

The battery is inserted correctly? plus visible

In which slots are the memory sticks installed?
Use only one and try this in each slot, beginning with the second slot from the left