My HP Z3200 printer has been performing almost flawlessly. That almost has been just a few times that the always-on cooling fan started making distressed sounds, like an electric motor not getting enough power. Restarting the printer brought it back to normal four or five times over ten months. But recently it did it more often, resulting in online support contact with HP. It sounded to me like a failing power source, and I realized I didn't have that much more time left on my warranty.
The phone interface you have to go through to get to an actual service tech is a nightmare, and the online interface—purpose of which is to make that easier—is even worse. But once you get to the service techs for the pro-level equipment they are very good. Yesterday a tech and I did a diagnostic on the machine. I had a phone in my left hand, and at times three fingers on different keys on the printer's front panel to access arcane diagnostic features. Then I had to read out various results. At the end he determined that the cooling fan/power source unit needed to be replaced so an onsite service was needed. Good thing it's still under warranty.
This afternoon Dave arrived, managed to get up the icy driveway, came in with the needed replacement part and commenced to dissect the entire left side of the machine.
as you can see here. But he got it all back together fine, and once again the printer made the familiar high clean note of the high-speed, always-on fan. Loaded a roll of paper back in and Dave asked for a test file. I pulled up a 20" wide print file, quickly sliced out a 6" horizontal strip and sent it to the printer. A few minutes later it was clear that the printer was working again, and with no ill effects to the heads or anything else that might affect print quality. So we're ready to rock.