iSelfSchooling.com  Since 1999     References  |  Search more  | Oracle Syntax  | Free Online Oracle Training

    Home      .Services     Login       Start Learning     Certification      .                 .Share your BELIEF(s)...

 

. Online Accounting        .Copyright & User Agreement   |
    .Vision      .Biography     .Acknowledgement

.Contact Us      .Comments/Suggestions       Email2aFriend    |

 

System Assembly 

Introduction to system assembly 

Assembly problems 

Causes of Electrostatic Discharge (ESD) 

ESD Damage 

Preventing ESD 

Prevention explained 

Electro-Magnetic Interference (EMI) 

Heat Problems 

Hardware Tools 

AT and ATX Power Supply 

Installing PSU in the case 

The CPU 

The Slot Processor 

The Socket Processors 

Installing the Processor 

Installing Memory 

Single Inline Memory Module (SIMM) 

Dual Inline Memory Module (DIMM) 

Computer Cases variety 

System Boards 

Installing the System board 

The IDE Hard Drive 

Installing the IDE Drives 

The Floppy Drive 

Installing Floppy Drive 

System Assembly

Introduction to system assembly

  • The goal of this module  is to introduce the user to system assembly , the process of building the system, the issues that you need to be aware of and finally the problems that you are likely to face. This module in effect guides you step by step as to how to install all the different components of your computer that include your PSU , system board , processor, memory , IDE  devices  and finally floppy drive

 

  • Electrostatic Discharge

  • Electrostatic Stability

  • Preventing ESD

  • Hardware  Tools

  • Multimeter

  • Installing the PSU

  • Installing the Processor

  • Installing memory

  • Installing the system board

  • Installing IDE  devices

  • Installing the floppy drive

 

 

 

Assembly problems

  • There are a number of dangers that one needs to have some awareness of and try and prevent when performing system assembly . The issues that could cause problems when installing or dealing with hardware are ESD , EMI  and Heat

Causes of Electrostatic Discharge (ESD )

  • Rubbing two surfaces to each other can generate static charge, which means that it can be generated in people by simply doing their routine tasks such as walking on a carpet or even dressing.

  • When two objects are at different electrostatic  potentials, in order for the higher potential object to become more stable or balanced, energy will flow in the form of electrostatic discharge from the object at the higher potential to the object with the lower potential.

  • Objects are only really electro statically   stable when they are grounded or at zero potential.

 

ESD  Damage

  • Electrostatic discharges above 2000 Volts are noticeable to the human body, but some computer components such as RAM  or CMOS  can be damaged with as little as 20 Volts.

  • ESD  is non recoverable which means the device will be permanently damaged.

 

Preventing ESD

  • Make sure the PSU  is firmly connected to the case  and the PSU is connected to the mains.

  • By connecting the PSU  to the mains you can ensure that the metal case  is always grounded.

  • You can use an anti-static wrist strap .

  • You can touch the system frame frequently.

  • You must handle the devices  very carefully.

  • You can use an anti static spray .

  • You can use an anti-static mat .

  • Change  external conditions

Prevention explained

  • In order to always be grounded, you should use an anti-static wrist strap , which clips on the metal part of the system case .

  • If you do not have an anti-static wrist strap  or find it difficult to work with them, you must touch the metal casing frequently in order to discharge regularly.

  • You must handle the devices  with care paying particular attention not to touch any of the naked contacts.

  • You can also apply some anti-static spray or a solution of fabric softener on the floor where you are working reducing the overall static charge in that region.

  • An anti static mat can be placed on the work desk beneath the computer again reducing the electrostatic  charge in the region. The mat must be grounded by connecting its clip to the metal case

  • Electrostatic discharge increases in dry cold environments, so it will be prudent to increase the humidity to levels above 70 percent. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Electro-Magnetic  Interference (EMI )

  • The motion of electrons in a wire causes a magnetic field around the wire.

  • This unwanted magnetic field could cause external noise to effect the data in a networked wire from the other power cables  resulting in data loss on the network  wire.

  • Devices which used magnetic fields for their operation such as hard drives, floppy derives, monitors can be adversely effected by EMI .

  • Unlike ESD , EMI  damage is recoverable.

 

Heat  Problems

  • The computer generally produces a great deal of heat and needs to be cooled down by heat sinks and fans. If the fan or heat sink was to stop working at any time and the system overheated, the computer will simply stop functioning and the screen freezes. In most instances this problem is recoverable once the system cools down and is rebooted. Some processors have been known to blow after an overheating  incidence but this occurrence is extremely rare. 

Hardware  Tools

  • There are a number of useful tools that you could use when working on a computer, the only essential tool that you require is the screwdriver.

  • Anti static wrist strap and Mat:à For dealing with electrostatic  charge.

  • Magnifying glass : à Useful for checking jumper  and dipswitch settings on some devices .

  • Tweezers :àUsed for removing jumpers or reaching areas that fingers find difficulty reaching.

  • Compressed air can: à blows dust of surfaces; computers, which are constantly ON, gather a lot of dust.

  • Multimeters  are a non-essential tool which can be used to measure electrical voltage, current and resistance.

  • There are two types of Multimeters , analogue (moving needle on the scale) and digital (have a digital display).

  • Only really used in our job when checking the PSU  or making sure of contacts, such as in fuses

 

 

 

 

 

 

 

 

 

 

 

 

 

 


AT  and ATX  Power  Supply

  • The AT  and ATX  Power  supply units (PSU ) convert  Alternating Current (AC) to Direct Current (DC).

  • The AT  PSU  has a power switch connected to it, and has connectors for power to the hard drive  and floppy drive  and other internal devices .

  • The AT  Power  supply also has the P8  and P9  connectors which connects to the AT system board .

  • The ATX  PSU  also has a P1  connector, which connect to the system board  and power connectors for the hard drive  and floppy drive .

  • The connector from the AT /ATX  PSU  to the system board  have operating voltages of 5V, 12V, –5V,     –12V, 3.3V

 

 

 

 

 

 

 

 

 

 

 

 

 


Installing PSU  in the case

  • You can install the PSU  in to the tracks in the case , and then use the screws to hold and tighten the power supply unit (PSU) in position. 

  • With an AT  system the P8  and the P9  connectors connect to the associated pins on the system board , make sure the black wires are at the center of the two connectors.

  • With an AT  system the power on switch is connected to the system case

  • With an ATX  system you need to connect the P1  connector to the system board .

  • ATX  has a power switch similar to the reset switch is directly connected from the case  to the system board  that gives the system the ability soft boot and shut down through the operating system .

  • Chapter 13

 

The CPU

  • There are two main designs for CPU  connectors on system boards, the socket  and the slot.

The Slot Processor

  • The Pentium  II processor like other slot processors (Pentium III, Xeon  II , Xeon III Processor  and some AMD  Athlon  Processors) has a board with the processor and cache  installed on it.

  • A plastic shell covers the processor with a heat sink connected to the shell. 

  • Some Celeron  processors are slot processors just like the Pentium  II processor but has less L2 cache  or no cache and no covering over it, but needs a heat sink to cool it down.

The Socket Processors

  • The socket  processor has a pin grid array (PGA ) design with pin 1 where the mark is on the processor.

  • Socket processors include 386 , 486 , Pentium , Celeron , P4, AMD  etc.

Installing the Processor

  • The socket  processor can be released over the socket, and it should easily slide in to place, do not force the chip in to the socket or processor pins may bend or break.

  • Place the slot processor over the track for the slot and then force it smoothly in to the slot.

  • Make sure the fan connection from the CPU  to the system board  in the correct pin socket .

  • Connect the three-pin fan connector from the processor to the associated pins on the system board

 

Installing Memory

  • There usually two types of memory  modules you are likely to use, a SIMM  and a DIMM  module . SIMM modules are in two separate designs, 30 pin  and 72 pin

 

Single Inline Memory Module (SIMM )

  • Both the 30 pin  and the 72 pin  SIMM  modules have a notch cut out of their corner which means the module  can only be installed in one orientation.

  • The 72 pin  modules are wider then the 30pin modules and have a small indentation in the center of the connectors.

  • When installing RAM  place the SIMM  module  with the correct orientation so that the notch on one side of the module matches with the extrusion on the SIMM connectors

Dual Inline Memory Module (DIMM )

  • The DIMM  module  has two separate notches on its contact end forcing the module to be installed in one orientation.

  • The DIMM  modules also have a cut on each of the edges for the connector grab and hold the module  in place

  • When installing the DIMM  module , it must be place over the connector in the correct orientation.

  • When the module  is in place; you slide the module on its tacks until it fits in to position.

  • You then proceed to give the module  a final push ensuring that the hammers on both sides of the connector close and grab on the notch in the DIMM  module.

 

Computer Cases variety

  • There are a variety of cases in the market, which suit the different needs of the consumer.

  • We can purchase very large cases for servers to small cases for desktop computers.

  • The mid tower case  is the most widely used case.

  • There are two main designs of computer cases you may come across these days, the AT  and the ATX  case

  • The AT  and the ATX  case  contain a place for installing a PSU , a hard drive , Floppy drive system board  etc.

  • The AT  case  contains only a place for aligning and the keyboard  and expansion card openings at the back of the PC.

  • The ATX  case  contains a place for aligning the keyboard , mouse , USB , soundcard, serial and parallel ports , and expansion card openings at the back of the PC.

  • The AT  case  contains a switch connected to the PSU  for starting the system.

  • The ATX  case  contains a switch connected to the system board  for soft booting the system

System Boards

 

  • The AT  board contains the keyboard  connector, expansion slots , SIMM  slots, cache , a processor socket , the BIOS  and the P8  and P9  pins for Power .

  • The ATX  board contains the PS/2  keyboard  and mouse  connector, USB  socket , parallel and serial ports, expansion slots , the EIDE  sockets and floppy socket, DIMM  slots, a processor socket or slot, the flash BIOS  and the P1  Power  socket.

Installing the System board

  • The system board  must be tightly screwed on the side panel

  • In some case  designs the side panel can be removed from the case.

  • It may be more prudent to install the system processor and ram prior to installing the system board  on to the case  although this task can also be performed after the system board installation  in to the case. Please check the modules installing the processor and installing the Memory prior to the next stage.

  • The side panel can then slide in to the main case .

  • For AT  systems the side panel must then be attached to the case  so that the din5 keyboard  connector can be seen correctly in place from the back of the case.

  • For AT  systems you must connect the cables for the parallel and serial connectors from the back of the case  to the appropriate pins on the AT system board  or the IO card for older systems.

  • The ATX  case  only allows for system board  to be oriented one way so that all of the external ports including keyboard , mouse , Serial ports, parallel port , sound ports, and SVGA  port are facing the back of the case behind the large opening in the case for these ports.

  • Screw the side panel in to the case

The IDE  Hard Drive

  • The IDE  hard drive  has a 40-pin socket , power socket and pins to set up the jumper  settings. The drive can usually be auto -detected by most modern systems.

  • The IDE  CD -ROM  drive has a 40-pin socket , power socket and pins to set up the jumper  settings. It also has a sound card  connector that allows sound to transmitted from the CD-ROM to the soundcard.

Installing the IDE  Drives

  • The IDE  cable  has two 40-pin connectors for two IDE devices  such as a hard drive, a CD -ROM  drive, ZIPP drive, and JAZZ  drive.

  • The IDE  cable  has a red line at one end-representing pin 1.

  • You must connect the IDE  connector from the cable  to the IDE socket  on the system board .

  • Pin1 on the socket  can be matched up with pin1 on the connector either by matching the red line on the cable  with the marked position of pin1 on the socket or by matching the notch on the connector to the slit on the socket.

  • Place the hard drive  in the drive panel on the case  beneath the floppy drive  and once it is in position screws can be connected through the case to the hard drive.

  • Place the CD -ROM  drive from the front of the case  until it fits in to position on the CD Drive /DVD  holder above the floppy drive , and then connect the screws through the case in to the drive.

  • One end of the IDE  cable  must be connected to the system board ; the other two connectors are connected to two IDE devices  (Hard drive, CD -Rom Drive, ZIPP Drive, JAZZ  Drive etc).

  • Pin1 on the socket  can be matched up with pin1 on the connector either by matching the red line on the cable  with the marked position of pin1 on the socket or by matching the notch on the connector to the slit on the socket.

  • The red line on the IDE  cable  usually matches with the red of the power connector

  • The cable  that transmits the sound from the CD -ROM  drive or the DVD  drive must be connected from the CD-ROM Drive to the sound card

The Floppy Drive

  • The main floppy drive  used these days in the market is the 3½-inch  1.44MB floppy drive.

  • This drive connects to a 34pin floppy connector and a small connector for the power in the back.

  • The floppy cable  can connect up to two floppy drives  to the system board .

  • The drive after the twist  is the A drive and the drive before the twist is the B drive.

Installing Floppy Drive

  • Place the floppy drive  from the front of the case  until it fits in to position on the lower drive holder above the hard drive , and then connect the screws through the case in to the drive.

  • You must connect the small power connector to the floppy drive . The connector can only connect one way

  • You must connect the Floppy connector from the cable  to the IDE  socket  on the system board .

  • Pin1 on the socket  can be matched up with pin1 on the connector either by matching the red line on the cable  with the marked position of pin1 on the socket or by matching the notch on the connector to the slit on the socket.

  • You can connect the floppy connector after the twist  to the A: floppy drive . Make sure you match the red on the cable  with pin1 on the floppy drive connector. The floppy drive does not always follow the convention of red of floppy cable matching with red of power cable.

  •  

 

Google
 
Web web site