1994 Honda Accord overheating

Long story made short, I bought a honda accord for my brother n law for his 16th birthday. The car was driven daily by my friend and it has ran hot before but it was supposivly fixed. I bought the car and gave it to my brother n law on his birthday. He drove his firiends around for a while here and there in the country and it was fine. We always kept the air on while going down the road cause the previous owner said he done it just incase it wanted to over heat. I never had a problem with it the 2 months I had it before the birthday. My father n law drove it around for a month or so here and there and it was fine. One day he turned the air off and it tried to over heat and since that day, it always over heats when they drive it. It has a new radiator, new a/c fan, new thermostat ( one that is "stick proof"), new coolant.
Is there anything that we can do to test if the head gasket is blown or the head is damaged. To my knowlege the fans are coming on like they are supposed to so that should eliminate the relays or switches shouldnt it. My brain is hurting from brainstorming on this issue. Any insight would be greatly appreciated.