There are several possibilities that you can check. First, what is the ink level for all colors? You need enough ink in all of the cartridges, black and the three color tanks in the color cartridge. A low ink in any one cartridge could do this.
Second, make sure you are printing on clean white letter or A4 paper (no additional print on the page). Is the paper feeding correctly from the paper tray? Did the alignment page print and arrive in the output tray? Check for a paper mismatch warning or if 4x6 paper selector lever is pushed forward on the output tray. Make sure the selector is pushed all the way towards the printer. Did the alignment page look like the previous alignment pages or the ones shown here: http://h10025.www1.hp.com/ewfrf/wc/document?docname=buu00657&tmp_task=solveCategory&lc=en&dlc=en&cc=us&product=60259#Alignment_Pages
If any color is missing, look for a problem with the cartridges. Try running a cleaning cycle: press Menu (or Setup, depending on the printer) on the printer. Press the right arrow until you see Maintenance or Tools. Press OK and then OK again if Clean Print Cartridges is highlighted. (Otherwise, highlight the Clean Print Cartridge by pressing the arrow keys and then press OK.) If the output is missing, faded, or streaked. Note: a low ink issue will be made worse with a cleaning. It is a cartridge issue. This could be a symptom of clogged nozzles on the cartridge, the protective tape still on the cartridge, or poor contact between the cartridge electrical contacts and the matching ones on the print head. Remanufactured and refilled cartridges are at higher risk of failing. However, the chip on the cartridge can also fail; in this case, if you have a genuine HP cartridge, contact HP. Replace the cartridges. You may want to clean the cartridges and the print head. Use distilled or bottled water and lint free paper or swabs. (coffee filters can be used.) Wipe away from the nozzles (the contacts, edges and ramps of the cartridge) of the cartridge and the contacts inside the printer. Wipe in one direction only even on the contacts inside the printer.
Reset the printer by unplugging the power cord for at least 5 seconds before plugging it back in. Print a new alignment page. Does the printer give one or two pages? If you only get one page, the alignment is automatic and you should see a blue light at times as the printer feeds and prints the page. If no light shows up, the printer needs service.
If you get two pages, check the scanner glass and white scan backing. Clean the surfaces with a soft cloth dampened with clean water, if they need cleaning. Check if the bulb assembly is lighting up when the unit is on. If that scanner light doesn't come on, the all-in-one needs service. Make sure to put the alignment page face down on the glass or face up in the ADF. Copy the alignment page. If the copy has vertical streaks, clean the scanner assembly. (If this cleaning doesn't help, again the unit needs service.)
You can bypass the required alignment. Press and hold the Enter button and then press the Setup button. The unit should print but the print quality will be poorer. If any colors are missing, check the ink level and for clogged nozzles.
I hope this helps.