- The three most commonly encountered types of printers are dot-matrix, ink-jet, and laser printers.
- As a computer technician, you can expect to encounter printing problems on a regular basis.
- Most printer problems can be resolved quickly by checking for paper jams, expended consumables, or improper use.
- The key components of a laser printer are its power supply, photosensitive drum, eraser lamp, primary corona, laser, transfer corona, and fuser.
- Modems convert parallel digital data to and from serial analog data.
- Modem speeds are based on bps (bits per second).
- CCITT (now ITU-T) establishes standards for modem communication.
- AT commands are used to manually communicate with and test a modem.
- Modems can be installed internally or externally.
- The primary modem problem is IRQ conflicts.
Cables and Connectors
- There are many different types of computer cables and connectors. It is important for the computer technician to be able to identify each of them.
- Distinguishing between a male or a female connector is often the key to identifying the connector's function.
- Loose or poorly connected cables are often the cause of computer problems.
- Name three types of printers and describe their advantages and disadvantages.
- The dot-matrix printer is an ____________ printer. Name at least one advantage of this type of printer. Name at least one disadvantage.
- What are the six steps of laser printing?
- Which components are usually included in a laser printer's replaceable toner cartridge? Why?
- What causes black spots to appear on a document that has been printed on a laser printer? How can this problem be resolved?
- What is the IEEE 1284 standard?
- What kinds of signals do telephones use? What kinds of signals do computers use?
- What is the purpose of a modem?
- Which AT command is used to take the phone off the hook?
- What is the difference between baud and bps?
- What is the name of the chip that converts data from parallel to serial?
- Name three transfer protocols.
- What is Zmodem? What are its advantages over other protocols?
- Define handshaking.
- What are AT commands and how can a computer technician use them?
- Explain the difference between half-duplex and full-duplex. What makes them different? Where or when is each used?
- What is the difference between synchronous and asynchronous communication?
- Why are fax standards different from modem standards?
- Describe a null-modem cable.
- In addition to the cost of the printer, what other costs should be considered when purchasing a printer?
- What does bps stand for?
- Identify as many cables and connectors as you can.
- What type of connector is used for a parallel port on the computer?
- What type of connector is used for a parallel port on the printer?