|This is the manual for that model: suggest you download and have a browse.|
It does show a PCIe graphics card as standard; with vga and dvi - one of each.
Page 17 is the start of connecting monitors... Might be worth a look-see?
Page 62 is a brief (very) what to check if no display...
It "might" be worth powering down (and removing the power cord too) and then removing the graphics card. Clean its edge connector with a soft pencil type eraser; after-which wipe contacts clean with a soft/lintless cloth of some sort. Re-install card and then remove again. Then re-install, reconnect monitor, power up and so on, and see if that resolves the problem? It might simply be the card has dislodged slightly in transit (not often happens but has been known).