Hp workstation xw8000 [intel pentium 3.40GHz 4.0GB DDR2 RAM,as spares or repair !

i have had his over a year but last week as i was using it,the computer screen went back but the pc is still on and since than it as not being coming on the screen but his on. i dont no much about commuter and i dont no what it will cost me to repair it,that is why am selling it as spares or repair as i have brought one yesterday.sold as seen hp workstation xw8000, [intel pentium 3.40GHz,4.0GB DDR2 RAM,80GB HDD]. COLLETION IN PERSON ONLY