pc turn on but no display

[paolooliveros10501]

Me and my freind were building a custom desktop for our CERT III IT class.
we finished the pc and turned it on. the pc turned on and we intalled window 10 32bit. the pc was working properly and we even ran benchmark testing. our motherboard did not had enough fan headers so we left one fan off. after we got a fan spliter we installed it and accidently took the front panels connectors out. after putting it back on the pc turns on but it does not have displays.
we tried reaseating every componant even cmos.
we replaced the ram.
we tried to turn it on without any fans plugged in to see if its a power issue.
and we had reseat the cmos battery and its a new motherboard so the battery is still new.
we tested the monitor and even replace it with others and replaced the vga port.
we took out our gtx 1030 and tried the onboard graphics.
we cannot update the bios because we dont have display and the pc was working perfectly fine.
the pecs are
amd ryzen 3 2200g
asrock AB350M-hdv
gtx 1030
thermaltake 650w power supply
8gb of ddr4 ram
and a 120gb kingston ssd

 

[SonicSkywalker]

Once I got a similar problem and all I did is swap the ram (like this ram to the other slot and that ram to this slot) and reset the cmos battery (remove the cmos battery for a couple of minutes then putting it back it) then it works.

 

[paolooliveros10501]

Thank you for your answer sonicskywalker we had switching the ram to a different slot
I will take your advise and takeout the cmos for a couple miniutes we had taken it off before but only for a couple of seconds