Troubleshooting print quality troubles for the HP LaserJet 2550 color laser printer based on a defective printout is a tough nut to crack. A laser printer is outfitted with several components; from mechanical rollers, to the photoreceptor drum, the toner cartridge and the fuser assembly. Each of these components is capable of inflicting toner smears on the printout. The only sure way to correct faulty prints is to pull out the suspect component responsible for pertinent print irregularities and physically check it for defects. However the process is tedious, because it involves ocular check-ups of selected, if not all components that come in contact with the paper (medium).
Measuring the Print Defect
Hewlett Packard however made troubleshooting for the HP 2550 so much easier with the use of a repetitive defect ruler. By measuring the actual dimension of the defect on paper (using a ruler), the ugly head of the suspect component can be identified. Since we are dealing with a defective OPC Drum, the repetitive defect measures 148.3 mm in length. Said measure actually indicates that such defect is produced by a defective photoreceptor drum. From thereon, the user simply needs to pull out the photoreceptor drum and physically assess its condition. If the defect is more pronounced, it has to be replaced and if defect is not visible, the drum probably just requires cleaning.
Replacing the Drum's Lockout Chip
Photoreceptor drums are designed with electronic based microchips or lockout chip that count the actual printed pages and consequently desist printing once the rating limit is breached. Standard capacity of the photoreceptor drum is from 6,000 to 8,000 copies at 5% coverage (the industry standard measure of page coverage) and the microchip nominally bars printing after the stated limit. However in cases where not a single defect manifests at the time printing stopped; it could only mean that the OPC Drum is still in fine form and the user will only have to change the lockout chip to commence printing.
Replacing the Drum Unit
On the other hand, if printouts have defects attributed to a defective OPC drum unit, a physical inspection of drum surfaces will not always be a sufficient indicator of the component's actual condition. A tear on its selenium coating is a visible defect (easily recognizable) but if the drum has lost its photosensitive properties, then no amount of physical inspection will be enough to determine what is really wrong with the component. In cases where the OPC drum is suspect and the defect persists, the only choice is to replace the OPC Drum.
Remember that while print defects are a regular fare for laser printers, most print quality troubles emanate from a toner low or toner empty, toner cartridge and seldom do these stem from faulty printer components. Defects attributed to toner empty cartridges can be resolved with the use of a compatible toner refill kit; where the supplied compatible toner powder is used to replenish the cartridge's toner supply. The bundled cost of OEM HP 2550 toner cartridges is around $350 with each cartridge having a capacity of 1,500 pages at 5% coverage. Read more about toner refill kits from our previous post.
For those operating on a shoestring budget, the compatible HP toner refill kit rainbow pack is retailed for less than $100 but delivers similar print performance and yield as the OEM toner.
Read a related post on How to determine if the laser printer drum needs to be replaced?
Measuring the Print Defect
Hewlett Packard however made troubleshooting for the HP 2550 so much easier with the use of a repetitive defect ruler. By measuring the actual dimension of the defect on paper (using a ruler), the ugly head of the suspect component can be identified. Since we are dealing with a defective OPC Drum, the repetitive defect measures 148.3 mm in length. Said measure actually indicates that such defect is produced by a defective photoreceptor drum. From thereon, the user simply needs to pull out the photoreceptor drum and physically assess its condition. If the defect is more pronounced, it has to be replaced and if defect is not visible, the drum probably just requires cleaning.
Replacing the Drum's Lockout Chip
Photoreceptor drums are designed with electronic based microchips or lockout chip that count the actual printed pages and consequently desist printing once the rating limit is breached. Standard capacity of the photoreceptor drum is from 6,000 to 8,000 copies at 5% coverage (the industry standard measure of page coverage) and the microchip nominally bars printing after the stated limit. However in cases where not a single defect manifests at the time printing stopped; it could only mean that the OPC Drum is still in fine form and the user will only have to change the lockout chip to commence printing.
Replacing the Drum Unit
On the other hand, if printouts have defects attributed to a defective OPC drum unit, a physical inspection of drum surfaces will not always be a sufficient indicator of the component's actual condition. A tear on its selenium coating is a visible defect (easily recognizable) but if the drum has lost its photosensitive properties, then no amount of physical inspection will be enough to determine what is really wrong with the component. In cases where the OPC drum is suspect and the defect persists, the only choice is to replace the OPC Drum.
Remember that while print defects are a regular fare for laser printers, most print quality troubles emanate from a toner low or toner empty, toner cartridge and seldom do these stem from faulty printer components. Defects attributed to toner empty cartridges can be resolved with the use of a compatible toner refill kit; where the supplied compatible toner powder is used to replenish the cartridge's toner supply. The bundled cost of OEM HP 2550 toner cartridges is around $350 with each cartridge having a capacity of 1,500 pages at 5% coverage. Read more about toner refill kits from our previous post.
For those operating on a shoestring budget, the compatible HP toner refill kit rainbow pack is retailed for less than $100 but delivers similar print performance and yield as the OEM toner.
Read a related post on How to determine if the laser printer drum needs to be replaced?
0 comments:
Post a Comment