Epson Stylus Photo R3000 printing light

[nemismom]

I just got my printer back from the shop, where the valves had to be replaced. When I tried to print a document, it came out light, as if in grayscale. I checked all my settings, and they are correct - matt black ink, plain paper, etc. I ran a nozzle check and it has no breaks, but it's all very light and the photo black and matt black patterns are blank. Of course, it's Friday night and my repair guy is closed all weekend. I installed a new matt black cartridge as the old one was low (but not out) and a new light, light black, as it was also low. Neither made any difference. The repair guy installed a new photo black cartridge, as he needed to in order to run test pages. I'd appreciate any thoughts on what might be causing this. Thanks!