Identify specification of types of fuses. Identification and specification of type of switches

Identify specification of types of fuses. Identification and specification of type of switches

Safety in moving and shifting heavy and delicate equipments.

 Safety   in   moving   and  shifting heavy and delicate equipment's.

https://www.youtube.com/watch?v=LqmZzTh7Kp8

Electrical Safety, Concept of Electrical Shock , General Safety Rules

Electrical Safety, Concept of Electrical Shock , General Safety Rules

Safety Signs & Symbols

 Safety Signs & Symbols

https://youtu.be/huEM80IlSFs

Safety Rules while using electronics

Safety Rules while using electronics

 https://youtu.be/yxdmSdsIHIQ

what is information and communication technology

 

what is information and communication technology

https://youtu.be/zkAr7P1S-c8

Theory-13 :- Laser Printing Process

 

Laser Printing Process

There Are Following Steps for Laser Printing Process

NOTE *easy way to remember this is CLEAN CARS WILL DRIVE TO FAST

1. Cleaning – The Photosensitive drum is cleaned before it can take on a new image
2. Conditioning or Charging – To make the drum receptive to new images, it must be charged. The EP drum is given a negative charge by the primary corona wire around ‐600 and ‐1000 volts
3. Writing ‐ A laser beam is use to write to the EP drum causing dots on the drum to lose some of the negative charge and become relatively positive charge
4. Developing ‐ A toner is transferred from the toner cylinder to the EP drum by attracting the area of the drum that has a   Relative positive charge
5. Transferring ‐ The transfer corona wire puts a highly positive charge on the paper once the paper has a positive charge the negatively charge toner particle leaps from the drum into the paper
6. Fusing ‐ The compression roller and fusing roller press and melts the toner into the paper the fuser gets very hot Laser printers generally follow the following processes to produce a page of print:

• Cleaning Conditioning
• Writing
• Developing
• Transferring
• Fusing

Cleaning Before a new page is printed; any remnants from the previous page are cleared away. The drum is swept free of any lingering toner with a rubber blade, and a fluorescent lamp removes any electrical charge remaining on the drum. Any toner removed in this step is not re‐used but is put into a used‐toner compartment on the cartridge.

Conditioning The entire drum is uniformly charged by the primary corona wire. This charge conditions the drum for the next step.

Writing The laser printer controller uses a laser beam and a series of mirrors to create the image of the page on the drum. The laser beam is turned on and off in accordance with the image to be created on the drum. At the spot where the laser's light contacts the photosensitive drum, the charge is reduced. After the entire image has been transferred to the drum, the controller starts the page sheet through the printer, stopping it at the registration rollers.

Developing A magnet inside the developing roller attracts the iron particles in the toner. This roller rotates near the drum and the toner is attracted to the areas of the drum that have been exposed by the laser, creating the print image on the drum.

Transferring The back of the paper sheet is given a positive charge that attracts the negatively charged toner from the drum onto the paper as it passes. After this step, the paper has the image of the page on it, but the toner, which is held only by simple magnetism, is not yet bonded to it.

Fusing The fusing rollers apply heat and pressure to the toner, which melts and presses it into the paper to create a permanent bond. The rollers are covered with Teflon and treated with a light silicon oil to keep the paper from sticking to them. Your printer will have come with a user manual that should explain the necessary cleaning and maintenance that should be undertaken. On the manufacturers' websites you will find a support section where you can download support details on their products.

Theory-12:-Laser Printer Components

Laser Printer Components

The following are the main parts of a laser printer:  

• Drum
• High‐voltage power supply
• DC power supply
• Paper transport
• Primary Corona
• Transfer Corona
• Fusing rollers
• Controller

Drum The drum inside the toner cartridge is photosensitive, which means it reacts to light. The drum holds an electrostatic charge (except where it is exposed to light). The laser beam is reflected onto the surface of the drum to create a pattern of charged and not-so-charged spots, representing the image of the page to be printed.

High‐voltage power supply The process uses very high voltage to charge the drum and transfer and hold the toner on the paper. The high-voltage power supply converts AC current into the higher voltages used by the printer.

DC power supply Like a computer, most of the electronic components in the laser printer use direct current. For example, logic circuits use +5V DC (volts direct current), and the paper transport motors use +24V DC.

Paper transport Inside the laser printer are four types of rollers that move the paper through the printer. Each rubberized roller or set of rollers is driven by its own motor. The four roller types in the paper transport system are the feed, registration, fuser and exit roller. This is where most paper jams in a laser printer occur.

Primary Corona Also called the main corona, this device forms an electrical field that uniformly charges the photosensitive drum to +600V to reset it prior to receiving the print image and toner.

Transfer Corona This mechanism moves a page image from the drum to the paper. The transfer corona charges the paper; the charge pulls the toner from the drum onto the paper. As the paper exits the transfer corona, a static charge eliminator strip reduces the charge on the paper so that it won't stick to the drum. Not all printers use a transfer corona; some use a transfer roller instead. When working on a printer with a transfer roller, be careful not to touch the roller. The oils from your skin can spot the transfer roller and cause improperly charged paper, resulting in defects in the printed image.

Fusing Rollers The toner is melted permanently to the page by the fusing rollers that apply pressure and heat (between 165 and 180C) to it. The fuser - not the laser - makes the printed pages hot.

Controller This is the motherboard of the laser printer, and it has architecture and components like a PC motherboard. The controller communicates with the PC, houses the memory in the printer, and forms the image printed on the page. Memory expansion is possible on virtually all laser printers. Adding memory allows the printer to reproduce larger documents or graphics in higher resolutions or to support additional soft fonts.

A printer that experiences frequent memory overflow errors may require more memory or has a bad memory board. Check what was being printed when the fault occurs, as memory overflow is more likely to be the cause.

Theory - 11:- how laser printer works

When you print something, your computer sends a vast stream of electronic data (typically a few megabytes or million characters) to your laser printer. An electronic circuit in the printer figures out what all this data means and what it needs to look like on the page. It makes a laser beam scan back and forth across a drum inside the printer, building up a pattern of static electricity. The static electricity attracts onto the page a kind of powdered ink called toner. Finally, as in a photocopier, a fuser unit bonds the toner to the paper.

1. Millions of bytes (characters) of data stream into the printer from your computer.
2. An electronic circuit in the printer (effectively, a small computer in its own right) figures out how to print this data so it looks correct on the page.
3. The electronic circuit activates the corona wire. This is a high‐voltage wire that gives a static electric charge to anything nearby.
4. The corona wire charges up the photoreceptor drum, so the drum gains a positive charge spread uniformly across its surface.
5. At the same time, the circuit activates the laser to make it draw the image of the page onto the drum. The laser beam doesn't actually move it bounces off a moving mirror that scans it over the drum. Where the laser beam hits the drum, it erases the positive charge that was there and creates an area of negative charge instead. Gradually, an image of the entire page builds up on the drum: where the page should be white, there are areas with a positive charge; where the page should be black, there are areas of negative charge.
6. An ink roller touching the photoreceptor drum coats it with tiny particles of powdered ink (toner). The toner has been given a positive electrical charge, so it sticks to the parts of the photoreceptor drum that have a negative charge (remember that opposite electrical charges attract in the same way that opposite poles of a magnet attract). No ink is attracted to the parts of the drum that have a positive charge. An inked image of the page builds up on the drum.
7. A sheet of paper from a hopper on the other side of the printer feeds up toward the drum. As it moves along, the paper is given a strong positive electrical charge by another corona wire.
8. When the paper moves near the drum, its positive charge attracts the negatively charged toner particles away from the drum. The image is transferred from the drum onto the paper but, for the moment, the toner particles are just resting lightly on the paper's surface.
9. The inked paper passes through two hot rollers (the fuser unit). The heat and pressure from the rollers fuse the toner particles permanently into the fibers of the paper.
10. The printout emerges from the side of the copier. Thanks to the fuser unit, the paper is still warm. It's literally hot off the press

Theory-15 :-Plotter and its common faults

Plotter and its common faults

A plotter is an output device that is used to produce high quality graphics in a variety of colors. Plotters are used to create maps, architectural drawings, graphs and charts.

Types of Plotters 

Different types of plotters are as follows:

1. Flatbed Plotter 
2. Drum Plotter

Flatbed Plotter:- Flatbed plotter is used to plot of draw images. It contains pens for drawing images. The paper is places on table‐like surface. Software instructs the pens to move down on the paper. The pen then moves on the paper for creating images. Most flatbed plotters have one or move pens of different colors and widths.

Drum plotter :- Drum plotter uses a rotating drum or cylinder. The drawing pens are mounted on the drum. The pens move to the left and right as the drum rotates. This movement creates the desired image. The advantage of drum plotter is that the length of the plot is almost unlimited. The roll paper can be used to draw very lengthy images. The width of the image depends on the width of the drum.  (Figure: Drum Plotter)

Today, mechanical plotters have been replaced by thermal, electrostatic and ink jet plotters. These systems are faster and cheaper. They also produce large size drawings. 

There are two main types of plotters for printing: flatbed plotters and drum plotters. Flatbed plotters use a system where the paper is fixed, and the plotter moves a pen up and down, and left and right to draw the required marks on the paper. Drum plotters move the pen up and down, and the paper left and right by rotating the drum. This enables drum plotters to have a footprint smaller than the final paper size. Plotters can use more than one pen, allowing different colors to be drawn.

   Dead Print Heads ‐ Over time, print heads will naturally wear out and need to be replaced just like brakes on your car. But, they can fail prematurely if they aren't properly cared for 

   

•     Non‐use is the biggest culprit to early print‐head failure
•     Each print head has thousands of microscopic nozzles which can clog with dried ink.  
•     The two easiest remedies are to 1) perform routine internal print head checks and calibrations and 2) leave your machine powered on so that the automated cycle maintenance can be performed.

   Paper Jams and Poor Stacking ‐ Most wide‐format printers rely on a gravity‐fed delivery system. In other words, the printed sheets simply fall out of the machine into a catch basket.

•    Often, jams and stacking issues are exaggerated by curled plans from ink jet printers.  If this is problematic, try printing on a heavier stock.
•     LED plotters can have issues with static electricity.  Although frustrating, this is an easy problem to correct with some anti‐static measures.  
•     Some systems offer flat stacking trays that are effective, but they can take up quite a bit of room.   
•      The new Océ plotters offer a top delivery system. 

.Software Compatibility ‐ This is a big one, especially where Windows 7 is concerned.  

    

•     Plotter manufactures systematically drop software support on older models when they announce an end to hardware support.  
•     Many tried and true legacy plotters won't be able to make the jump to Windows 7.
•     Be sure to check on 64 bit compatibility in addition to Windows 7 support.  
•    Unfortunately, sometimes the only fix is to upgrade your printer technology with your operating system. The good news is that the price of wide‐format printers is significantly less than when you spent $8,000 on that HP1055 eight years ago

Theory- 14:-Line Printer

Line Printer      

The line printer is an impact printer in which one line of text is printed at a time. They are mostly associated with unit record equipment and the early days of digital computing, but the technology is still in use.

A line printer is a high‐speed printer capable of printing an entire line of text at once instead of one or more characters at a time. These types of printers are too fast to be measured in words or characters per minute, and instead are measured in lines per minute. For example, a line printer may be capable of printing over 3,000 lines of type per minute.

A high‐speed printer capable of printing an entire line at one time. A fast line printer can print as many as 3,000 lines per minute. The disadvantages of line printers are that they cannot print graphics, the print quality is low, and they are very noisy.

Line Printers: ‐ Line Printer can Print One Line at a Time. The line printer is a form of high speed impact printer. They can Print 300 to 3000 Lines per Minute. So that they are very fast. Large Computer system typically uses Line Printer. The Line Printers are of two Types.

Drum Printers: ‐ Drum Printer consists of a Drum Which Consists of a Number of Characters; those are Printed on the Drum. And the Number of Characters or Number of Tracks are Divided, after examining the width of the Paper. But there are also Some Character sets Available Means the Number of Characters those are printed on the Paper. For Example 64, and 96 Characters etc.

In this Paper is placed between the Ribbon and the Head or Hammer there are many hammers on the Front of Drum. In this Drum Rotates at a Very High Speed and character is printed by activating the Appropriate Hammer. So always remember that All the Characters are never printed at a Time, but they are printed at a very high Speed. And they can print only a Pre Defined Styles because the Drum has a Specific Characters. Those are placed on the Drum. So that they cant print the various Types of Fonts and Color Pictures. And Drum Printers are also noisy because they use Hammering Techniques.

Chain Printers: These are also Line Printers, which Prints one Line at a Time. All the Characters are printed on the Chain and the Set of Characters are placed on the Chain. There are 48 and 64 and 96 Characters set Printers are Available. There are also Some Hammers, those are Placed in Front of the Chain, and Paper is Placed between the Hammer and the Inked Ribbon. The Total Number of Hammers will be Equals to the Total Number of Print Positions.

In this Chain Rotates at a Very High Speed and Character is printed by activating the Appropriate Hammer of the Character. Chain Printers can also print some Pre Defined characters and we can’t Display the High Quality of Fonts and Font Styles. They are also Impact Printers and Also Noisy because they Prints the Characters by Hammering Action. And these Printers can print the 400 to 3000 Lines Per Minute.

Theory-10 :- Types Of Printers

A printer is any device that prints text or illustrations on paper. There are many different types of printers. In terms of the technology utilized, printers fall into the following categories:

1. daisy‐wheel: Similar to a ball‐head typewriter, this type of printer has a plastic or metal wheel on which the shape of each character stands out in relief. A hammer presses the wheel against a ribbon, which in turn makes an ink stain in the shape of the character on the paper.Daisy‐wheel printers produce letter‐quality print but cannot print graphics.

2. dot‐matrix: Creates characters by striking pins against an ink ribbon. Each pin makes a dot, and combinations of dots form characters and illustrations.

3. ink‐jet: Sprays ink at a sheet of paper. Ink‐jet printers produce high‐quality text and graphics.

4. laser: Uses the same technology as copy machines. Laser printers produce very high quality text and graphics.

5. LCD & LED :Similar to a laser printer, but uses liquid crystals or light‐emitting diodes rather than a laser to produce an image on the drum.

6. line printer: Contains a chain of characters or pins that print an entire line at one time. Line printers are very fast, but produce low‐quality print.

7. thermal printer: An inexpensive printer that works by pushing heated pins against heat‐sensitive paper. Thermal printers are widely used in calculators and fax machines.

What is a Printer? A printer is an electromechanical device which converts the text and graphical documents from electronic form to the physical form. Generally they are the external peripheral devices which are connected with the computers or laptops through a cable or wirelessly to receive input data and print them on the papers. A wide range of printers are available with a variety of features ranging from printing black and white text documents to high quality colored graphic images.

Quality of printers is identified by its features like color quality, speed of printing, resolution etc. Modern printers come with multipurpose functions i.e. they are combination of printer, scanner, photocopier, fax, etc. To serve different needs there are variety of printers available that works on different types of technologies.

Types of Printers Since the invention of the printing technology, a variety of technologies have been employed in computer printers. Broadly printers are categorized as impact and non impact printers. Impact printers are the type of printers in which a key strikes the paper to make a letter. The examples of Impact printers are Daisy wheel and Dot matrix printers. While non‐impact printers do not operate by striking a head against a ribbon. Inkjet printers and laser printers are the non‐impact printers. The most popular printers are described.

1.     Daisy Wheel Printers Daisy wheel printers print only characters and symbols and cannot print graphics. They are generally slow with a printing speed of about 10 to 75 characters per second. By 1980 daisy wheel printers were the dominant printers for quality printing but since the prices of laser and inkjet printers have declined and quality of dot matrix printers has been improved, the daisy wheel printers are now obsolete.

Working of daisy wheel printers is very similar to typewriters. A circular printing element (known as daisy wheel, shown in the below image) is the heart of these printers that contains all text, numeric characters and symbols mould on each petal on the circumference of the circle. The printing element rotates rapidly with the help of a servo motor and pauses to allow the printing hammer to strike the character against the paper.

 2. Dot Matrix Printers It is a popular computer printer that prints text and graphics on the paper by using tiny dots to form the desired shapes. It uses an array of metal pins known as print head to strike an inked printer ribbon and produce dots on the paper. These combinations of dots form the desired shape on the paper. Generally they print with a speed of 50 to 500 characters per second as per the quality of the printing is desired. The quality of print is determined by the number of pins used (varying from 9 to 24).

3. Inkjet printers Inkjet printers are most popular printers for home and small scale offices as they have a reasonable cost and a good quality of printing as well. A typical inkjet printer can print with a resolution of more than 300 dpi and some good quality inkjet printers are able to produce full colored hard copies at 600 dpi. An inkjet printer is made of the following parts: ∙         

Print head – It is the heart of the printer which holds a series a nozzles which sprays the ink drops over the paper. ∙        

 Ink cartridge – It is the part that contains the ink for printing. Generally monochrome (black & white) printers contain a black colored ink cartridges and a color printer contains two cartridges – one with black ink and other with primary colors (cyan, magenta and yellow).

Stepper motor – It is housed in the printer to move the printer head and ink cartridges back and forth across the paper. .       

Stabilizer bar – A stabilizer bar is used in printer to ensure the movement of print head is précised and controlled over the paper. .     

Belt – A belt is used to attach the print head with the stepper motor. .      

Paper Tray – It is the place where papers are placed to be printed. .     

Rollers – Printers have a set of rollers that helps to pull paper from the tray for printing purpose. .      Paper tray stepper motor‐ another stepper motor is used to rotate the rollers in order to pull the paper in the printer. .    

Control Circuitry – The control circuit takes the input from the computer and by decoding the input controls all mechanical operation of the printer.   

Similar to other printers, inkjet printers have a ‘print head’ as a key element. The print head has many tiny nozzles also called as jets. When the printer receives the command to print something, the print head starts spraying ink 33 over the paper to form the characters and images. There are mainly two technologies that are used to spray the ink by nozzles. These are: ∙        

 Thermal Bubble – This technology is also known as bubble jet is used by various manufacturers like Canon and Hewlett Packard. When printer receives commands to print something, the current flows through a set of tiny resistors and they produce heat. This heat in turn vaporizes the ink to create a bubble. As the bubble expands, some of the ink moves out of the nozzle and gets deposited over the paper. Then the bubble collapses and due to the vacuum it pulls more ink from ink cartridge. There are generally 300 to 600 nozzles in a thermal printer head which can spray the ink simultaneously. ∙        

 Piezoelectric – In the piezoelectric technology, a piezo crystal is situated at the end of the ink reservoir of a nozzle. When printer receives the command to print, an electric charge is applied to the crystal which in turn starts vibrating and a small amount of ink is pushed out of the nozzle. When the vibration stops the nozzle pulls some more ink from the cartridge to replace the ink sprayed out. This technology is patented by Seiko Epson Corporation.   

An inkjet printer can print 100 to several hundred papers depending on the nature of the hard copy before the ink cartridge need to be replaced.

4. Laser Printers Laser printers are the most popular printers that are mainly used for large scale qualitative printing. They are among the most popularly used fastest printers available in the market. A laser printer uses a slight different approach for printing. It does not use ink like inkjet printers, instead it uses a very fine powder known as ‘Toner’. Components of a laser printer are shown in the following image:

The control circuitry is the part of the printer that talks with the computer and receives the printing data. A Raster Image Processor (RIP) converts the text and images in to a virtual matrix of dots. The photo conducting drum which is the key component of the laser printer has a special coating which receives the positive and negative charge from a charging roller. A rapidly switching laser beam scans the charged drum line by line. When the beam flashes on, it reverses the charge of tiny spots on the drum, respecting to the dots that are to be printed black. As soon the laser scans a line, a stepper motor moves the drum in order to scan the next line by the laser.  

Theory - 20 :- Multi Function Device ( All in One)

An MFP (Multi Function Product/ Printer/ Peripheral), multifunctional, all‐in‐one (AIO), or Multifunction Device (MFD), is an office machine which incorporates the functionality of multiple devices in one, so as to have a smaller footprint in a home or small business setting (the SOHO market segment), or to provide ...

MFD (Multi Function Device) integrates all these four functions into a single device. Therefore you only buy a single machine and save money and space. There are many MFD brands such as HP, Epson, Canon, Lexmark, Samsung and Brother are available. The price of most of these MFDs are affordable.

MFDs are also called 'All‐in‐One' device. Printing, Scanning, Photocopying and Faxing all in one device. Most people now do not use FAX and therefore

there are many MFD models without FAX

A product or device that has multiple functions. An example of this might be a printer that also makes copies, faxes, and scans. Another example is a CD or DVD that might contain multiple applications on the same disk; this may be a Mac and PC version of the same software or media meant to be played on more than one platform. Also called multi function product (MFP), all‐in‐one.

A product or device that has multiple functions. An example of this might be a printer that also makes copies, faxes, and scans. Another example is a CD or DVD that might contain multiple applications on the same disk; this may be a Mac and PC version of the same software or media meant to be played on more than one platform. Also called multi function product (MFP), all‐in‐one

A multifunction peripheral (MFP) is a device that performs a variety of functions that would otherwise be carried out by separate peripheral devices. As a rule, a multifunction peripheral includes at least two of the following:

•  A printer
•  A scanner
•  A copier
•  A fax machine

Multifunction peripheral devices often have a base function with one or more added capabilities. Here are some common examples:

• Digital copy machine: Creates copies digitally, by scanning and printing. In addition to scanning and printing, may include fax, sorter and office hardware, such as a stapler
• Fax machine MFP: Looks like a normal fax but connects to a PC for data input/output, printing, scanning and copying.
• Printer/Scanner/Copier MFP: Performs all three functions and sometimes faxing as well. Cost savings and lower space requirements make multifunctional peripherals a practical choice for many people who would ordinarily have to buy separate devices. On the other hand, those who require high‐end functioning may be better served by a device dedicated to that particular use.

A Multifunctional Device, or MFD, is typically the printing device in most offices but is referred to as a printer or photocopier. These machines incorporate scanning, copying and printing as a minimum, into a single device – some can also be used for emailing and faxing.

 

Practical-9 :- How to clean printer head?

 AIM :- How to clean printer head?

Equipment:-   

• Printer Head
• Trainee Tool Kit:

Theory: -

A blocked printer head greatly affects the performance of the printer. It may be caused by dried ink because it has not been used for a long period of time. This causes poor printing job leading to waste of ink and paper and may eventually damage the printer. It is extremely important to clean out the printer head when it is clogged.

Procedure :- 

How To Clean Print Heads - Instructions for Printer Head Cleaning

If a printer has not been used for a long period of time, the many tiny holes that make up a modern inkjet printer's head may become clogged with dried ink. Clogged printer heads greatly affect the quality of the printing job and can eventually lead to damage to the printer. It is very important to clean out printer heads when they are clogged.

Printer Self-Cleaning

Most inkjet printers have some sort of automatic utility program by which you can instruct the printer to go through a self-cleaning cycle. A number of these cleanings, in succession, will usually take care of a clogged printer head. However because the cleaning cycle needs to be repeated multiple times, a significant amount of ink can be consumed during this process - as much as 10-25% of the cartridge's ink.

If the self-cleaning cycle does not solve the problem, try turning the printer off overnight to allow the ink to soften. Turn the printer on the next day and try printing a test pattern to see whether the problem has either disappeared or become less noticeable. This ink-saving procedure can work effectively because sometimes the dried ink on the print head needs time to soften before the printer head can be cleaned completely. Try running the self-cleaning utility again one or more times.

 

Steps for Manually Cleaning the Printer Head

If the overnight cleaning still does not work, there may be a layer of thick ink that is blocking the holes of the printer's head. The next option is to manually clean the printer head. Follow these steps:

·         Determine from the owner's manual where the print head is located.

·        Remove the ink cartridge from your printer and then dip a cotton swab in hot water or isopropyl alcohol and rub it against the print head. This should loosen any crusted ink. NOTE: Be careful, especially if you use isopropyl alcohol to clean your print heads: Some printers use rubber gaskets, and if you get isopropyl alcohol on the gaskets it could dry them out.

·     For models where the print head is in the printer, drop 7 to 10 drops of isopropyl alcohol (91% denatured isopropyl alcohol - not 'rubbing' alcohol) down the ink receptacle area where the ink actually flows from the cartridge into the head. Run a few self-cleaning utilities. If possible, allow the printer to sit a few hours or overnight and repeat the self-cleaning utility.

·      If the print head is in the cartridge, soak the cartridge print head in hot water. Allow it to soak overnight. Dry the print head area with a paper towel. Repeat the self-cleaning utility.

·       If the hot water soak did not unclog the print head, place the cartridge printer head in isopropyl alcohol and allow it to soak overnight. Use a damp paper towel to wipe off the print head area and dry carefully. Try the self-cleaning utility again.

·     If the alcohol soak did not unclog the print head in the cartridge you may need to purchase a new cartridge. This will provide new print heads that won't be clogged. Contact a service technician for repair of print heads in the printer if the alcohol did not unclog the printer head.

Preventive Maintenance

It's a good idea to regularly conduct preventive maintenance on your inkjet printer to prevent it from developing clogged printer heads. Some steps you can take include:

·     Since print heads become clogged when not used for long periods of time, regularly print a page or two to keep the print heads clear. Some experts say that it is better to print one colorful page a week than to run a printer cleaning cycle, because doing so uses a lot less ink.

·     Turning the printer off when it is not in use can save the printer head from getting clogged with dried ink. Leaving the printer on keeps the ink in the cartridge warm and can make it bleed onto the printer head.

·      If you need to store your printer it would be best to take the printer cartridge out. Be careful to never touch the printer head with oily or dirty hands - this can leave skin oil on the printer head and add to the possibility of it getting clogged.

·         Ideally, printer cleaning cycles should be started once a week to prevent the printer head from getting clogged.

There are other more ink-efficient ways to be able to clean printer heads that will prevent their clogging just as effectively as running the printer's cleaning cycle:

• Brush the printer heads with Q-tips soaked in water. Sources vary on whether alcohol would be more effective than water, but in the opinion of some printer experts alcohol can be harmful to printer heads and should thus be avoided.
• Buy a cleaning kit and use it regularly on your printer. A typical cleaning kit usually has a tube of ammonia that you can spray on the printer head to remove dried ink.
• Covering the printer when not in use to keep it free from dirt and debris also helps prevent the printer heads from getting clogged.

 

 

Practical - 8 :- HOW TO REFILL TONER CARTRIDGE

Aim :- HOW TO REFILL TONER CARTRIDGE

Equipment: - Printer Cartridge

Row Material: - Toner Powder For Printer

Theory: - A toner cartridge, also called laser toner, is the consumable component of a laser printer. Toner cartridges contain toner powder, a fine, dry mixture of plastic particles, carbon, and black or other coloring agents that make the actual image on the paper.

Procedure :- 

Step 1: Unscrew the both end of the hp 12 toner cartridge. Total you will find 4 screws.

Step 2: Open the drum side cover by just pulling it from drum gear side.

Step 3: Get out the drum by simply sliding the drum by side.

Step 4: Remove the magnetic roller by slightly making gaps and inserting the twiser on the other side of the hp 12 a toner.

Step 5: Remove the magnetic roller washer by the twiser.

Step 6: Open the other end of the cartridge by pulling it gently until it separated.

Step 7 : Separate the other end of the hp 12 a toner cartridge. Do not remove the gears

 Step 8 : You have successfully separated the cartridge. Then you will get two part, one is waste toner part and other is empty toner part.              

Step 9: Get out the tension spring located at waste toner part.

Step 10: Remove the drum pressure roller from the waste toner part of the hp 12 a cartridge

Step 11: You will see the wiper blade just below the pressure roller. Unscrew and remove the wiper blade and clean it by soft cloth. Do not twist the transparent blade part.

Step 12: You will see waste toner dust beneath the wiper blade. Remove the waste dust completely with the help of brush. And clean it gently by a soft cloth. Do not   damage the plastic film blade that is stick on the cartridge.

Step 13: Fix the wiper blade and fasten the screw gently.

Step 14: Clean the drum pressure roller by soft cloth and check for any dry sticky dust on the roller. If necessary, clean the roller by a wet cloth.

Step 15: Fix the pressure roller to its position.

Step 16: Make empty the tonner unit is any dust remains.

Step 17: Shake well the tonner dust before refilling. Pour the dust by help of a piece of paper.

Step 18: Assemble the both unit of the cartridge gently. Check for correct adjustment i.e, no gaps remains on the either sides of the hp 12 a toner cartridge. Do not make excess pressure during assembling, simply make the position it will get its position softly.

Step 19: Clean the magnetic roller with a soft cloth. Do not rub hard thoroughly.

Step 20:Fix the gear and washer of the magnetic roller.

Step 21: Fix the magnetic roller gently. Locate the spring part of the magnetic roller 'D' shaped. Match the shape with the cartridge body.

Step 22: During fixing of the magnetic roller you have to make slight gap so,that the gear gets its right position.

Step 23: If necessary use a new drum for the best result. Place the drum by gently sliding to the cartridge body. Do not touch the drum area, hold the drum by its gear.

Step 24: Fasten all the screws.

Step 25: Place the tension spring by the help of a twiser.

Step 26: Just get test print....Enjoy.