Question No Video output from PC

[rokaszz]

No video output from computer, monitor is still functioning and fully working on old mobo. I bought a cpu+mob+ram combo tried to run it and get no display from pc tried with gpu and without it, tried to run it in single ram didn't work i did settle ram fully, pluged all the cables, so what could be the problem has the mobo failed?
about the mobo its hp lga 1155 with i5-3570, 4x2gb ram ddr3 1333mhz

 

[rgd1101]

exact model of this hp? some of them might not work with 3rd gen or might need an bios update to work with 3rd gen

 

[rokaszz]

exact model of this hp? some of them might not work with 3rd gen or might need an bios update to work with 3rd gen

It was used like this before so i dont think it needs bios update

 

[rgd1101]

so what is this

. I bought a cpu+mob+ram combo tried

 

[rokaszz]

so what is this

I m saying that the same guy sold his mobo, cpu, ram that he was using