Z370-I Gaming --- Black Screen Issue

[BRUNEZ]

Hi,
Yesterday evening after change pwm fan (inside the bios), push apply and the MOBO be freeze.
After wait 2 minutes this freezing diplay i push reset on case button and after continue to reset and start automatically.
So… i disconnect energy, wait one minute and try to power on, but now the PC start without any video signal, try to use 8700K vga or 980 but not change.
I try to disconnect the battery and give again but nothing, and impossible to go inside the bios.
This mobo don 't have any reset o clear Cmos button.

Wait any suggestion, thanks a lot to all.

[BRUNEZ]

OK, solved.
I forgot to write that this problem arrive after some cleaning works operation on liquid cooling.
Today with air pressure i clean inside Ram slot and all work fine now.

Bye.