Computer Repair

Don ShappelleAdam Blaisse

Online Resources

• http://www.donshappelle.com

Supplemental documentation, videos and presentations.

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Computing 101

Source: http://www.warepin.com/wp-content/uploads/2010/01/categories-of-a-computer-hardware-3.jpg

Binary Numbers

• Base of two (0 or 1)• A single digit is a “bit”, can be 1 or 0.• 1= on, true & 0 = off, false• 11101010 to decimal:

Source: http://www.mathsisfun.com/binary-number-system.html

Hexadecimal Numbers

• Base of 16, easily translates to binary (base 2)0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F

• Not case sensitive (D is same as d)

Source: http://www.mathsisfun.com/hexadecimals.html

Kilo, Mega, Giga & Tera

• KB = about one thousand bytes (210)• MB = about one thousand KB or a million

bytes (220)• GB = about one thousand MB or a billion bytes

(230)• TB = about one thousand GB or a trillion bytes

(240)

NOTE: 210 is actually 1,024, so 1KB is really 1,024 bytes

Hardware

• Motherboard & BIOS• CPU, Power & Cooling• Memory• Storage Devices

Inside Your Old Computer

Source: http://upload.wikimedia.org/wikipedia/commons/d/d4/Quick_overview_of_pc_hardware.jpg

Inside Your New Computer

Source: http://g-ecx.images-amazon.com/images/G/01/electronics/cybertron/cybertronpc-fortressiv-internals-lg.jpg

Motherboard

• Printed Circuit Board (PCB) with expansion capability

• Holds many crucial components, like CPU & Memory

Descriptive Motherboard component diagram available at: http://computech-teluu.blogspot.com/2010/04/components-layout.html

Motherboard

• Most common is Advanced Technology Extended Motherboard (ATX), since 1995

Descriptive Motherboard component diagram available at: http://computech-teluu.blogspot.com/2010/04/components-layout.html

Source: http://upload.wikimedia.org/wikipedia/commons/9/9d/Acer_E360_Socket_939_motherboard_by_Foxconn.svg

Cooling

• Fan: attached to the heat sink to increase the airflow

• Heat Sink: piece of metal that draws heat from the CPU and dissipates it

• Thermal Paste: fills microscopic gaps between CPU and heat sink, aids in drawing heat from CPU

BIOS

• Basic Input/Output System• Built Into PC• First Software Run When Powered On• Press F2 for “System Setup” (Example)• Stored on a Chip that was originally Read Only• Can be rewritten, updated (called “Flashing”)

Source: http://en.wikipedia.org/wiki/BIOS

CPU

• Central Processing Unit (THE BRAIN!)• Most of Processing, key factor in performance• Primary Manufacturers:

Intel (85%) & Advanced Micro Devices (AMD)• Choose a CPU compatible with Motherboard• Advanced RISC Machine (ARM) processors are

used in tablets and mobile devices, no fans, run with less power. (not usually replaced)

32 bit vs 64-bit

• A 64-bit CPU is required to run a 64-bit operating system.

• A 64-bit operating system is required for 64-bit applications.

• A 64-bit CPU will also run 32-bit software.

Note: 32-bit Machines MAX OUT at ~3.5GB RAM

CPU Cores & More

• A “core” is a fully functioning processor• With Multiple cores, tasks can be divided

among them, making it faster to process• Examples (Intel-based):

P4 HT, Pentium D, Core 2 Duo, i3, i5, i7

Complete List of Processors:http://en.wikipedia.org/wiki/List_of_Intel_microprocessorshttp://en.wikipedia.org/wiki/List_of_AMD_microprocessors

Note: Hyper Threading allows a CPU to process two threads (groups of instructions) at a time, simulating two physical CPUs.

Random Access Memory (RAM)

• Short-term storage of applications or data• Allows processor to access and use

information• NOT THE SAME AS A HARD DRIVE, which is

used to store long-term data• VOLATILE – data is lost when power is lost.

RAM-related definitions• Dynamic RAM (DRAM)• Synchronous DRAM (SDRAM) • Static RAM (SRAM)• Double Data Rate (DDR) SDRAM• DDR2• DDR3• DD4• Dual in-line memory module (DIMM)• Small outline dual in-line memory module (SODIMM)• Single, Dual and Triple Channel• Single-Sided, Double Sided• Parity• Error Correction Code (ECC)

Storage Devices

• Hard Drives• Solid State Drives• Connection Types• Floppy Disk Drives• Optical / Combo Drives & Burners

Hard Disk Drive (HDD)

• Primary long-term storage device• Non-volatile• Uses spinning platters (up to 15k RPM)

covered with ferromagnetic material.• Data is written by magnetizing that material.

Hard Disk Drive (HDD)Physical components:Platters. Hard drives have multiple spinning platters, and each platter can be writtento on both sides.Read/write head. A hard drive will have one read/write head for each platter side.Actuator. The actuator controls the movement of the arm.Actuator arm and axis. The actuatorarm is moved back and forthby pivoting around the actuator axis. This positions the read/write head on different areas of the platter.

Hard Disk Drive (HDD)Logical components:

Tracks. Each platter is logically divided into multiple tracks, which are circular areas on the disk. When the head is positioned over a track, it can read or write data on the track as the platter spins.Sectors. Tracks are logically separated into track sectors. A sector can be between 512 bytes and 2 KB in size.Clusters. A cluster is a group of multiple sectors. Clusters are also known as allocation units and are the smallest element of a drive to which an operating system can write.

Solid State Drives (SSDs)

• Have no moving components• Use only electronics to store/retrieve data• Commonly seen in USB Flash Drives, Tablets• Faster Transfer Rates (as fast as 500MB/s)

Connection Types

• IDE• SATA• eSATA• SAS

Source: http://www.serialstoragewire.org/images/articles/it24fig1.jpg

Floppy Disk Drive

• Drive Letters A and B• Can hold up to 1.44 MB• Old version 5.25”• New version 3.5”• Rarely Used Now

Optical Drives (Disc, not Disk)

Types and SpeedsR (Recordable). A recordable disc can have data written to it once. It is sometimesreferred to as write once read many (WORM) and is used for backups and archives.It is possible to write the data in multiple sessions, but after an area is written on thedisc, it cannot be rewritten. The R applies to CDs (as in CD-R), DVDs (as in DVD-R), andBlu-Ray discs (as in BD-R).

RW (Rewritable). A rewritable disc can be rewritten many times. The RW applies toCDs (as in CD-RW) and DVDs (as in DVD-RW).

RE (Recordable Erasable). Blu-Ray discs use RE (as in BD-RE) to indicate that the discis rewritable.

Speeds:CD: 150 KBpsDVD: 1.39 MBpsBlu-Ray: 4.5 MBps

So, a 16X DVD-writer can write at 1.39MBps*16, or approximately 20MBps

Optical Disc Extraction Tool (ODET)

Questions, Comments, Suggestions?

• Ask on the site at http://www.DonShappelle.com

• Supplemental material available there for review and/or download