Lost power to printer after cleaning mirrors in optical box

Hi,
I received a similar HP Laserjet Color Printer with same issue for repair/ maintenance a few months back. This is a common issue with HP 1600 and 2600 Printers.
Actually, the problem is with the printer design not the cartridges and it needs professional hands for servicing and cleaning. The mirrors which reflect laser beam get covered with dust and toner. Hence, the image is not produced properly/ sharp. (It is because of the reason that the image forming laser beam does not fully reflected by the mirrors as they are covered with dust/ toner) Note that first magenta goes off, followed by yellow, then cyan and lastly black. This is because of the mirrors placement inside the printer.

Rest assure that the printer requires ONLY CLEANING OF THE MIRRORS, which are inside the printer.

Clean them yourself with dry n soft cloth (if you are familiar with such tasks, if not you may seek professional assistance) or get it cleaned by any printer repair/ service professional. The printer has to be disassembled partially by removing the outer covers and the Laser Scanner Unit to clean the optics. Please note that the mirrors, lenses and scanner assembly inside such printers is extremely complex and can get damaged very easily especially the mirrors. So, it is recommended that if you are not comfortable and experienced enough with working inside/ disassembling such devices, get the printer serviced by authorized professional results.

Let me know if any further clarification/ assistance is required.

Hope it helps! Good Luck! Thanks for using Fixya!
CreativeTECH

I have worked/ serviced similar Laserjet Color Printer with same issue.
Actually, prints with faded colors or different colors are due the the dust/ toner dust accumulated on the optics (mirrors and lenses) inside the printer, which refect the laser beams to form prints. For instance, red color is formed by a mix of yellow and magenta toners. The color is replaced by yellow due the the partial or complete blocking of the image laser beam for magenta as the mirrors which reflect laser beam get covered with dust and toner (which partially blocks the laser beams). Hence the image is not produced properly. This needs professional hands for servicing and cleaning of the optics inside the printer. Note that first magenta goes off, followed by yellow, then cyan and lastly black. This is due to the mirrors placement inside the printer. Magenta is the last one facing upwards at 45 degrees angle and gets most of the dust and goes off first.

Rest assure that the printer requires ONLY CLEANING OF THE MIRRORS, which are inside the printer. So, it is advised that you get the printer serviced by any printer repair/ service professional. (Please note that the mirrors, lenses and scanner assembly inside such printers is extremely complex and can get damaged very easily especially the mirrors).

Hope it would help. If you need any clarification, let me know
Good Luck!
CreativeTECH

I have worked/ serviced similar Laserjet Color Printer with same issue.
Actually, prints with faded colors or different colors are due the the dust/ toner dust accumulated on the optics (mirrors and lenses) inside the printer, which refect the laser beams to form prints. For instance, red color is formed by a mix of yellow and magenta toners. The color is replaced by yellow due the the partial or complete blocking of the image laser beam for magenta as the mirrors which reflect laser beam get covered with dust and toner (which partially blocks the laser beams). Hence the image is not produced properly. This needs professional hands for servicing and cleaning of the optics inside the printer. Note that first magenta goes off, followed by yellow, then cyan and lastly black. This is due to the mirrors placement inside the printer. Magenta is the last one facing upwards at 45 degrees angle and gets most of the dust and goes off first.

Rest assure that the printer requires ONLY CLEANING OF THE MIRRORS, which are inside the printer. So, it is advised that you get the printer serviced by any printer repair/ service professional. (Please note that the mirrors, lenses and scanner assembly inside such printers is extremely complex and can get damaged very easily especially the mirrors).

Hope it would help. If you need any clarification, let me know
Good Luck!
CreativeTECH

I have worked/ serviced similar Laserjet Color Printer with same issue.
Actually, prints with faded colors or different colors are due the the dust/ toner dust accumulated on the optics (mirrors and lenses) inside the printer, which refect the laser beams to form prints. For instance, red color is formed by a mix of yellow and magenta toners. The color is replaced by yellow due the the partial or complete blocking of the image laser beam for magenta as the mirrors which reflect laser beam get covered with dust and toner (which partially blocks the laser beams). Hence the image is not produced properly. This needs professional hands for servicing and cleaning of the optics inside the printer. Note that first magenta goes off, followed by yellow, then cyan and lastly black. This is due to the mirrors placement inside the printer. Magenta is the last one facing upwards at 45 degrees angle and gets most of the dust and goes off first.

Rest assure that the printer requires ONLY CLEANING OF THE MIRRORS, which are inside the printer. So, it is advised that you get the printer serviced by any printer repair/ service professional. (Please note that the mirrors, lenses and scanner assembly inside such printers is extremely complex and can get damaged very easily especially the mirrors).

Hope it would help. If you need any clarification, let me know
Good Luck!
CreativeTECH

I have worked/ serviced similar Laserjet Color Printer with same issue.
Actually, red color is formed by a mix of yellow and magenta toners. As the color is replaced by yellow it is clear that the problem is with the the magenta cartridge or most probably the mirrors which reflect laser beam get covered with dust and toner (which partially blocks the laser beams). Hence the image is not produced properly. This needs professional hands for servicing and cleaning of the optics inside the printer. Note that first magenta goes off, followed by yellow, then cyan and lastly black. This is because of the mirrors placement inside the printer. Magenta is the last one and gets most of the dust and goes off first.

Rest assure that the printer requires ONLY CLEANING OF THE MIRRORS, which are inside the printer. Clean them yourself with dry n soft cloth (if you are familar with such tasks) or get it cleaned by any printer repair/ service professional. Please note that the mirrors, lenses and scanner assembly inside such printers is extremely complex and can get damaged very easily especially the mirrors.

Hope it would help. If you need any help in cleaning mirrors and lenses let me know
Good Luck!
CreativeTECH

I received a similar HP Laserjet Color Printer with same issue for repair/ maintenance a few months back.
Actually the problem is with the printer design not the magenta cartridge and it needs professional hands for servicing and cleaning. The mirrors which reflect laser beam get covered with dust and toner. hence the image is not produced properly. note that first magenta goes off, followed by yellow, then cyan and lastly black. this is because of the mirrors placement inside the printer.

Rest assure that the printer requires ONLY CLEANING OF THE MIRRORS, which are inside the printer.

Clean them yourself with dry n soft cloth (if you are familar with such tasks) or get it cleaned by any printer repair/ service professional. Please note that the mirrors, lenses and scanner assembly inside such printers is extremely complex and can get damaged very easily especially the mirrors.

Hope it would help, looking forward

Print a "Config Report" from the printers menu...If u notice that the fourth square on the left side (fourth being the bottom square) for Magenta (reds and orange) is missing or very faded, this could indicate that the optical mirrors inside the printer have to be cleaned...Design flaw. ESP..if changing toners doesn't work and your your faded issue is with Magenta (Pink, red, or orange) colours are the only faded ones...With this design flaw in the optical mirrors, magenta mirror is the first to be affected!
Hope this helps!!!! I work in the industry :)

This is likley to be the common problem (with this model of printer) of the laser unit having dirty lenes and/or mirrors.

Typically the magenta is the first colour to deteriorate.

To rectify this problem there's a fair bit of dismantling to be done in order to get the laser unit out.

Then you can open the laser unit up and clean the lenses and mirrors CAREFULLY. You don't want to scratch the surface silvered mirrors, or disturb the alignment of any of the optical components.

You'll see the same problem and solution for HP1600, HP2600, and Canon LBP5000, as they all use the same laser unit.

replace magenta developer unit

Following the suggestions above I have just resolved this problem. My exact problem was that the Magenta colour was printing out at different densities across the page - from faint at either side to solid in the middle. 
The procedure I followed was to dismantle the printer until I could get at the laser/scanner unit, take that out, and take the top off. I discovered that the mirror for the magenta toner was very dusty so I cleaned it with a cotton bud (dry, no water or solvent for fear of damaging the surface coating of the mirror), taking the opportunity to clean all the others at the same time. 
After reassembling, the printer is now perfect again. I did not perform any resets or recalibrations following this operation.
Some comments:
1. Disassembling is a fairly complex job, involving disconnecting most of the loom from the back PCBs. You need to do this to be able to remove the rear internal panel so that you can get at the laser/scanner assembly. Don't worry too much. though, because all the plugs are different sizes so it should be fairly straightforward reassembling it all. It worked out fine for me!
2. The bottom screw for the laser/scanner assembly (in my case, although there are actually holes for two screws) is located behind two thin metal panels which spring out from the bottom of the printer body, just above the paper tray.
3. I think there is a bit of a design flaw in these printers (if it's fair to describe it as such). Two of the mirrors (magenta and yellow) are angled upwards so that dust can collect on them, while the other two are angled down. Of the two that are angled up, the Magenta one is at the bottom and is most likely to collect dust. The laser/scanner assembly is not sealed so it is easy for dust to get into it. Furthermore there is a fan alongside the bottom mirror so there will be more dust in the air in this area. It would not surprise me if this is a fairly common problem for these printers after a certain amount of use.