Introduction to the Xerox® Phaser®7500 & 7800 printers

The Phaser® 7500, and 7800 which followed, make some stunning full color prints. They are also designed with some new innovative technologies which reduce energy consumption. They are well received in the market and there are quite a few of them out there nowadays. Some of the 7500s are beginning to come off contract so they’re beginning to show up in the aftermarket. It’d be a good idea to learn a bit about them.

In this article, we’ll take a quick look at the new technologies which these machines utilize. We’ll also focus on the Fault Code meanings and how to clear some of the faults from diagnostics (the codes which require resetting).
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The first innovation is that instead of using a traditional Laser Unit or Raster Output Scanner (ROS) assembly, these use LED arrays (LPH = LED Print Heads). In the brochures, they call the technology “Hi-Q® LED” technology; the advantages are that the LEDs use less energy and are quieter than a machine using a laser with its ROS motor constantly spinning the mirrors. I imagine that with less mirrors and no moving parts, this solid-state design will likely require less attention, although time will tell if the LED bars hold up or if they develop problems later in life.

The newer model, Phaser 7800, also introduces a new type of fuser, which uses Induction Heater (IH) technology. Taking a Phaser 7800 fuser apart leaves one with more questions about how it works than answers. Induction Heating is definitely alien to what we are all used to seeing. It is said to require less energy, especially in standby, and yet it has a far quicker warm up time (15 seconds compared to 46 seconds for the 7500 model which has a more traditional design using good ol’ heat lamps).
Phaser 7500 & Phaser 7800

So, just how green are these machines in the final analysis? Let’s compare the stats from the OEM brochures for these two models with the Phaser 7760 that these guys replaced.

It appears that the newer models are indeed more efficient, especially when you see that they use less than half as much power at standby. Not sure why the 7800 shows a higher wattage use during printing and so high a wattage in Power Save. Maybe the tradeoff with the new Induction Heater is that it takes more power to run prints when called on. Pretty cool stuff.

Now here is an abbreviated list of the Fault Codes which the machine may report. The codes with asterisks next to them require resetting from Diagnostics. We’ll have a peek at how to clear tech rep codes later on. The full list in the Service Manual is over 300 lines long, so this list has been trimmed down with generalization about some groups of faults (010-xxx are all fuser faults, for example) and then the list goes on to list a few of the specific ones of particular interest because they are either common or they require resetting from Diagnostics.

This is a pretty quick glimpse. At least with this list you’d have a rough idea where to look in the machine if a fault code is coming up on screen.

GRAY chart_FaultCodes_pt1GRAY chart_FaultCodes_pt2Note: **Some faults (marked with asterisks) will not r­eset by themselves. Once you have repaired the cause of the fault, you will need to go in and clear the fault before the machine will even attempt to get printing again. Below is how to clear tech rep faults:

1. Hold down ‘Back’ and ‘Help’ buttons together while turning the printer on.

2. Continue to hold the buttons until you see “Service Diagnostics V. x.xxx, Initializing” on the display; you can then release the two buttons.

3. Scroll down through the Service Diagnostics Menu and select “NVRAM Access”. In the subm­enu which shows up, scroll down to “Clear Tech Rep Faults”. Choose this and then look for the fault you are experiencing and reset it.

You can also choose from the same “NVRAM Access” list: “Reset CRU Life Counters”. This is necessary if you are replacing any of the Customer Replaceable Units (CRU) such as the Fuser Module, Transfer Roll Assembly, Belt Cleaner Assembly or Toner Waste Bottle.

Well, hopefully that should do the trick to get everyone started at least. We’ll have to return to this series and find out more about what else you can do from Diagnostics in a future article. Happy repairs everyone.u

­Britt works for The Parts Drop, a company whose primary business is providing parts, supplies and information for Xerox brand copiers, printers and fax machines. You can find more information, including many of Britt’s past ENX articles on their website, www.partsdrop.com. If you’d like to read more about Xerox brand office equipment, there’s also a complete listing of past articles under contributing writers on the ENX website (www.ENXMAG.com).

Britt Horvat
About the Author
Britt Horvat works for The Parts Drop, a company whose primary business is providing parts, supplies and information for Xerox brand copiers, printers and fax machines. You can find more information, including many of Britt’s past ENX articles on their website www.partsdrop.com.