Same exact thing happened to me. We've printed less than 100 pages since December after putting a brand new (expensive) HP toner cartridge into the printer. The cartridge was supposed to yield 2,400 pages.
Everything was fine until the other night when I heard the printer turn itself on and the light turned amber. Hours of troubleshooting have not fixed the issue and then I saw an article about this happening to other people.
I am completely disgusted with HP. This needs to be fixed immediately at no cost to consumers. We didn't break our printers -- HP did.
Because we needed to print documents for one of my husband's classes, we bought an Epson ET-2850. I guess the HP is just a huge paperweight now until HP does right by their customers.