Question Please help - no post no keyboard

[rodgerdooter]

Hi all I have the most frustrating problem

specs
Ryzen 3600
Asrock b450 steel legend
Silver stone 700 psu
Gtx 1070
Corsair rgb pro 32gb
Samsung 970 eve ssd

My system has been working fine , until I decided to upgrade my motherboard to an ASU’s rog b550 . I installed all my parts but the pc just will not post , everything turns on , lights up and spins but no signal to monitor and no keyboard lights up

tried everything , one stick of ram , re seating and clearing cmos . After I few days I think sod it … I will go back to my old motherboard

problem is now , back on my old motherboard it’s doing the same thing , everything turns on , spins and lights up but no post and no keyboard

what can it be

 

[MEMOFLEX]

Have you checked the cpu for bent pins?

 

[rodgerdooter]

I did , but only a quick glance - a man look
Maybe I’ll start there , and give it a clean too

 

[rodgerdooter]

Ok , day 6 of this nightmare

cpu is back off - no pins are bent
I have noticed a small amount of paste in the pins thou - and I’m talking tiny amounts - I’ll clean it , but I’m not convinced it’s enough to be the problem

 

[rodgerdooter]

Everything apart , assembled in breadboard on the old motherboard - it’s now posting , and will post into windows once an ssd is added :-/