Question fuzzy screen on start up or restart, no bios access

I observed if i shut down pc and turn off power on power supply switch, then push power on switch on case, led fans flash for a few seconds, then turn power back on at power supply switch, and turn the system on, i get the motherboard logo and bios access, after that if i restart or from reboot, i get the multi colored screen instead of motherboard logo and bios access.
 
I observed if i shut down pc and turn off power on power supply switch, then push power-on switch button on case, led fans flash for a few seconds, then turn power back on at power supply switch, and turn the system on, i get the motherboard logo and bios access, after that if i restart or from reboot, i get the multi colored screen instead of motherboard logo and bios access.