1999 Saturn SL2 failed emissions

I took our car for inspection and failed for emissions. The reason was because the scanner could not read the obd. I asked the state about the failure, and they said it was a no voltage read. However a hand scanner will read the obd just fine. The service light is not on and there are no detected codes, if I make the light come on and throw a code, the hand scanner reads it just fine. I correct what I did and clear the codes with no problem. Some people have suggested checking all the fuses. I can not find any blown. So what else could I possibly do?