b. Problems associated with laser printers and probable causes:
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1. Speckled pages: The causes for this may be
-
a. The failure to clean the drum after printing properly,
or
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b. The drum might have developed scratches.
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2. Blank pages: The causes for white pages may be
-
a. . The toner would have dried out, replace the toner.
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b. The transfer corona, that is responsible for transferring
the toner to the drum might have failed.
-
c. The High Voltage Power Supply (HVPS) failure will
also result in white pages.
-
3. Ghosted Images: Ghosting occurs when previously printed
pages are printed again, though much lighter than the present
image. The most likely cause is that the erasure lamp might
not be working properly, thus leaving some charges representing
the earlier image left on the photosensitive drum before new
image is written. Also check the cleaning blade, which is responsible
for scraping the residual toner.
-
4. Smudged images: If the fusing fails, the toner will not
bond with the paper. Check the halogen lamp responsible for
heating.
c. Typically, a laser printer maintenance kit consists of fuser
fixing assembly, pickup rollers, transfer roller, gloves, and instruction
manual.
2. Impact printers
-
a. Impact printers are capable of printing multipart forms,
since they can give necessary impact to print to multiple forms
simultaneously.
-
b. ECP (Extended Capability Port) has less control overhead
and best suited for transferring large chunks of data, such
as between the computer and laser printer.
3. InkJet Printers
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InkJet Printers is the generic name given for contact less
printing using ink. Friction feed is most commonly used with
laser printers, and Inkjet printers. One needs to check the
calibration for the inkject printer if it is not printing properly.
If it doesn't help, then check the ink cartridge if it requires
replacement.
4. Thermal printers
-
Thermal printers require a special kind of paper, called
thermal paper. This paper is sensitive to heat, and the printing
is produced by thermal heat applied on the paper by the print
head.
4.2 Given a scenario, install, and configure
printers
1. Printer parallel ports come in the following varieties
-
a. Unidirectional: Here, the data travels only from the computer
to the peripheral (printer) device.
-
b. Bi-directional: Here, the data travels both from the computer
to the peripheral device and vice-verse.
-
c. ECP (Extended Capability Port): ECP mode offers bi-directional
data transfer, as well as DMA for data transfer.
-
d. EPP (Enhanced Parallel Port): In addition to bi-directional
features, it offers an extended control code set
-
e. The port that a printer is using can be found by going
to Control Panel -> Printers and right click on appropriate
printer. Choose Ports tab to view the port (like COM1, COM2,
USB001, etc.) that the printer is using.
2. Cable lengths
-
a. Serial cable maximum length is 50 feet.
-
b. Parallel cable maximum length is 10 feet.
-
c. Longer cable lengths may lead to some errors & garbage
characters.
3. RJ – cables
-
a. RJ-11: These connectors are used to link modem / phone
to the phone line. They have only two pins that get into the
modem.
-
b. RJ-14: RJ-14 connectors are dual-line phone jacks that
can accommodate up to 2 telephone line.
-
c. RJ-45: RJ-45 cable is widely used for attaching UTP cable
in LAN environment. These connectors have eight pins.
-
d. The widely used interface cables have the following pin
count:
-
floppy-34 pin
-
IDE-40 pin
-
SCSI-50 pin
-
SCSI Ultra wide-68 pin
4. Ultra IDE cable has 80 wires, and handles better speeds compared
to IDE cable with 40 wires. The additional wires are introduced
to reduce noise and thereby improving speed
5. Thin co-axial and thick co-axial cables have conductive grounding
sheath surrounding the center conductor. Therefore, the electromagnetic
interference (EMI) is significantly less.
6. Cat 6 cabling is recommended for Gigabit Ethernet networking.
7. Centronics cable, used for parallel printing will have a male
DB-25 connector at one end and a female 36 pin connector at the
other end.
8. The default spool folder is located at: Systemroot\System32\spool\printers.
For example, if the OS is residing on C drive, the default location
will be: “C:\\Windows\System32\spool\printersâ€Â.You can access
this location through:
-
Start -> Printers -> File -> Server Properties ->
Advanced tab. Type in the new spool location over the default
location.
9. While connecting a printer using USB if Operating System is
not recognizing the USB port you need to make sure that the USB
interface is enabled in the BIOS. Note that Windows 95, Windows
NT4.0 (Upto service pack 4) do not support USB. Also, make sure
that the motherboard BIOS supports USB.
10. A network printer can be added to Windows XP computer by
going to Control Panel (classic view), Printers and Faxes applet,
This will initiate Add Printer wizard. In Category View, choose
Printers and Other Hardware hyperlink and select Add Printer option.
11. When a printer is installed on a network, default printer
permissions are assigned that allow all users to print. Because
the printer is available to all users on the network, you might
want to limit access for some users by assigning specific printer
permissions. For example, you could give all non-executive users
in a department the Print permission and give all managers the Print
and Manage Documents permissions. You can also deny print permission
to all others. In this way, all non-executive users and managers
can print documents, but managers can also change the print status
of any document sent to the printer.
12. If you share a printer with users running other versions
of Windows (Windows 98, XP, Vista, etc), you can install additional
printer drivers on your computer so those users can connect to your
printer without being prompted to install the drivers missing from
their systems.
13. Scanner installation process is much like a print device.
Because so many of these now are USB, plugging them in will install
the driver. In cases where that does not work (usually when it is
a very new model and the operating system is older), use the installation
disc to install the driver.
Monitors, speakers, and projectors normally do not require a
driver to perform.
14. A scanner driver is usually called TWAIN. The Twain driver
will always have another name, for example, Microtek calls theirs
ScanWizard, and HP calls it as DeskScan or PrecisionScan. The TWAIN
driver comes with the scanner, and knows how to operate this one
brand of scanner hardware. Each scanner manufacturer provides their
own TWAIN driver for their hardware.
15. Windows XP provides three levels of printing security permissions:
Print, Manage Printers, and Manage Documents. When multiple permissions
are assigned to a group of users, the least restrictive permissions
apply. However, when Deny is applied, it takes precedence over any
other permission.
-
a. Print: The user can connect and print document. By default,
the Print permission is assigned to all members of the Everyone
group.
-
b. Manage Printers: The user has complete administrative
control of the printer. The user can pause and restart the printer,
change spooler settings, share a printer, change printer permissions,
and change printer properties. By default, the Manage Printers
permission is assigned to members of the Administrators and
Power Users groups.
-
c. Manage Documents: The user can pause, resume, restart,
cancel, and rearrange the order of documents submitted by all
other users. The user cannot, however, send documents to the
printer or control the status of the printer. By default, the
Manage Documents permission is assigned to members of the Creator
Owner group.
16. In Windows 7 Operating System, most printers and other peripheral
devices are automatically detected and drivers are installed. Therefore,
first you must see if the OS itself recognizes the device and installs
the drivers. If you are prompted to locate the driver, the browse
to the driver location and direct the installation.