I have a hp 3800 that will not print from the yellow or the Magenta cartridge. Prints for the black and cyan ok. I have put it in Diag. mode and switched the carts. around and they all work well. I have marked the two carts. not working and they are turning. I was on the phone with my tech support for over an hour and we thought we could change the high voltage board, guess what that didn't do it. Well being I was already there I changed the dc controler, didn't help. I just really can't think of anything I have not done that may help. The only thing left is get on the internet and ask for help, well here I am. HELP!!!!