Thursday, December 22, 2011

The Major Motherboard Components and their Functions

THE MOTHERBOARD

The main printed circuit board in a computer is known as the Motherboard. It is also known as System Board, Main Board or Printed Wired Board (PWB). Attached to it, we have numerous motherboard components that are crucial in the functioning of the computer.
The motherboard acts as the connection point where major computer components are attached to. It holds many of the crucial components of the system like the processor, memory, expansion slots and connects directly or indirectly to every part of the PC.
The type of motherboard installed in a PC has a great effect on system speed and expansion capabilities.

MOTHERBOARD COMPONENTS

The motherboard holds all the major logic components of the computer. Here we are going to see with no particular order, some of those major motherboard components and their function in a computer or to be more precise in your computer.


A core 2 Duo Intel Processor

CPU- Central Processing Unit
It is also known as the microprocessor or the processor. It is the brain of the computer, and it is responsible for fetching, decoding and executing program instructions as well as performing mathematical and logical calculations.
The processor chip is identified by the processor type and the manufacturer; and this information is usually inscribed on the processor chip e.g. Intel 386, Advanced Micro Devices (AMD) 386, Cyrix 486, Pentium MMX, (old processor types) Intel Core 2Duo e.t.c.
If the processor chip is not on the motherboard, you can identify the processor socket as socket 1 to Socket 8, LGA 775 e.t.c. This can help you identify the processor that fits in the socket. For example a 486DX processor fits into Socket 3.


Memory Modules
Main Memory / Random Access Memory (RAM)
Random access memory or RAM most commonly refers to computer chips that temporarily store dynamic data when you are working with your computer to enhance the computer performance. In other words, it is the working place of your computer where active programs and data are loaded so that any time time the processor requres them, it doesn't have to fetch them from the hard disk which will take a longer access time.


Random access memory is volatile memory, meaning it loses its contents once power is turned off. This is different from non-volatile memory such as hard disks and flash memory, which do not require a power source to retain data. When a computer shuts down properly, all data located in random access memory is returned back to permanent storage on the hard drive or flash drive. At the next boot-up, RAM begins to fill with programs automatically loaded at startup, and with files opened by the user a process called booting.


BIOS Chip
BIOS- Basic Input Output System
BIOS is a term that stands for basic input/output system, which consists of low-level software that controls the system hardware and acts as an interface between the operating system and the hardware. Most people know the term BIOS by another name—device drivers, or just drivers. In other words, the BIOS is drivers, meaning all of them. BIOS is essentially the link between hardware and software in a system. 


All motherboards include a small block of Read Only Memory (ROM) which is separate from the main system memory used for loading and running software. On PCs, the BIOS contains all the code required to control the keyboard, display screen, disk drives, serial communications, and a number of miscellaneous functions.
The system BIOS is a ROM chip on the motherboard used by the computer during the startup routine (boot process) to check out the system and prepare to run the hardware. The BIOS is stored on a ROM chip because ROM retains information even when no power is being supplied to the computer.


CMOS Battery
CMOS-Complimentary Metal Oxide Semiconductor
Motherboards also include a small separate block of memory made from CMOS RAM chips which is kept alive by a battery (known as a CMOS battery) even when the PC’s power is off. This prevents reconfiguration when the PC is powered on.
CMOS devices require very little power to operate.
The CMOS RAM is used to store basic Information about the PC’s configuration e.g.
  • Floppy disk and hard disk drive types
  • CPU
  • RAM size
  • Date and time
  • Serial and parallel port information
  • Plug and Play information
  • Power Saving settings
The Other Important data kept in CMOS memory is the time and date, which is updated by a Real Time Clock (RTC).


L2 Cache on an old Motherboard

Cache Memory
It is a small block of high-speed memory (RAM) that enhances PC performance by pre-loading information from the (relatively slow) main memory and passing it to the processor on demand.
Most CPUS have an internal cache (in-built in the processor) which is referred to as Level-I cache memory or primary cache memory. This can be supplemented by external cache memory fitted on the motherboard. This is the Level-2 Cache memory or secondary cache. Some CPUs have both L1 and L2 cache built-in and designate the separate cache chip as Level 3 (L3) cache.


PCI Slots

Expansion Buses
An input/output pathway from the CPU to peripheral devices typically made up of a series of slots on the motherboard. Expansion boards (cards) plug into the bus. PCI is the common expansion bus in a PC and other hardware platforms. Buses carry signals, such as data; memory addresses, power and control signals from component to component.
Expansion buses enhance the PCs capabilities by allowing users to add missing features in their computers in form of adapter cards that are slotted in expansion slots.
The different types of buses include PCI, ISA, and EISA expansion bus.
ASUS M4A77TD PRO ATX Motherboard AM3 AMD 770 W/RAID Audio & GbLAN


ASUS M3A78-T ATX Motherboard AMD 790GX AM2+/AM2 W/HDMI DVI Video GbLAN


DELL PowerEdge SC430 MotherBoard M9873 0M9873 LGA 775


Intel SE7320EP2 604-pin micro-PGA ATX DDR2-400 New Board Only For SC5275 SC5295


Intel Model D915GAG / D915GRV LGA775 Desktop PC System Board Motherboard


Dell Inspiron 6000 Intel MotherBoard X9237 in Case Bottom


Chipset

A chipset is a group of small circuits that coordinate the flow of data to and from key components of a PC. This includes the CPU itself, the main memory, the secondary cache and any devices situated on the buses. The chipset also controls data flow to and from hard disks, and other devices connected to the IDE channels. A computer has got two main chipsets:-

  • The NorthBridge (also called the memory controller) is in charge of controlling transfers between the processor and the RAM, which is way it is located physically near the processor. It is sometimes called the GMCH, for Graphic and Memory Controller Hub.
  • The SouthBridge (also called the input/output controller or expansion controller) handles communications between peripheral devices. It is also called the ICH (I/O Controller Hub). The tem bridge is generally used to designate a component which connects two buses.
Chipset manufacturers include SIS, VIA, ALI, OPTI e.t.c.

Cpu Clock
The clock synchronizes the operation of all parts of the PC and provides the basic timing signal for the CPU. Using a quartz crystal, the CPU clock breathes life into the microprocessor by feeding it a constant flow of pulses. For example, a 200 MHz CPU receives 200 million pulses per second from the clock. A 2 GHz CPU gets two billion pulses per second. Similarly, in a communications device, a clock may be used to synchronize the data pulses between sender and receiver.

A "real-time clock," also called the "system clock," keeps track of the time of day and makes this data available to the software. A "timesharing clock" interrupts the CPU at regular intervals and allows the operating system to divide its time between active users and/or applications.


Dip switch on an old motherboard.

Jumper pins with a cap on
Switches and Jumpers
DIP (Dual In-line Package) switches are small electronic switches found on the circuit board that can be turned on or off just like a normal switch. They are very small and so are usually flipped with a pointed object such as a screwdriver, bent paper clip or pen top. Care should be taken when cleaning near DIP switches as some solvents may destroy them.

Jumper pins
Jumpers are small pins on the board with plastic or metal devices that go over the pins. This device is called a bridge or a jumper cap. When the bridge is connected to any two pins via a shorting link, it completes the circuit and a certain configuration has been achieved.

Jumper cap
A metal bridge that closes an electrical circuit. Typically, a jumper consists of a plastic plug that fits over a pair of protruding pins. Jumpers are sometimes used to configure expansion boards. By placing a jumper plug over a different set of pins, you can change a board's parameters.

Wednesday, December 21, 2011

Nokia Codes Tips and Tricks


To check the IMEI (International Mobile Equipment Identity) Type-
*#06#
Information you get from the IMEI-
XXXXXX  XX  XXXXXX  X
    TAC      FAC     SNR      SP

  • TAC = Type approval code
  • FAC = Final assembly code
  • SNR = Serial number
  • SP    = Spare
To check the phones Software revision type-
*#0000#
Information you get from the Software revision-
V 05.31
18-02-99
NSE-3
  • 1ST Line  = Software revision
  • 2ND Line = The date of the software release
  • 3RD Line = Phone type
To enter the service menu type-
*#92702689# (*#WAR0ANTY#)
  • Serial number (IMEI)
  • Production date (MM/YY)
  • Purchase date (MM/YY) You can only enter the date once.
  • Date of last repair (0000=No repair)
  • Transfer user data to another Nokia phone via Infra-Red
Clock Stopping
To check weather your SIM Card supports clock stopping type-
*#746025625# (*#SIM0CLOCK#)

Revealing the Headphone and Car-Kit menus
Please note that if you do these next tricks, the new menus can't be erased without retoring the factory default settings. To do these tricks you need to short-circuit the pins on the bottom of the phone next to where you plug in you charger.

1. To activate the "Headset" menu, you need to short-circuit pins "3" and "4". After a short time the word "Headset" will be shown in the display. Menu 3-6 is now enabled.
2. To activate the "Car" menu, you need to short-circuit pins "4" and "5". After a short time the word "Car" will be shown in the display. Menu 3-7 is now enabled.

THE REBOOT TRICK
This should work on all software versions of the 6110.
1. Go to the Calendar (Menu-8)
2. Make a note or reminder.
3. Enter some text into the edit box.
4. Hold "Clear" until the whole text is cleared, then press "Back".
5. Press "0". The main screen will now be showing but a space appears on the screen. (you can't see it)
6. Enter 4 digits (e.g. 1234).
7. Use the down arrow to move the cursor to the left side of the numbers and the space (Down arrow twice).
8. Now enter 6 digits and press the call button.

Wait for a few seconds, the screen should start to flash and reboots. It should alsowork on other menus like the "Profiles" menu.

EFR CALL QUALITY
To activate EFR (Enhanced Full Rate) Enter the code-
*3370#
This improves call quality but decreases batterylife by about 5%
To deactivate it, Enter the code-
#3370#

THE JAMES BOND TRICK
If you short-circuit theleft middle and right pins on the bottom of the phone with all connections touching each other, the Nokia software hangs! The profile "Headset" will be activated. Before you do this just activate the "Automatic Answer" in the headset profile and set the ringing volume to "Mute". Now you can use your phone for checking out what people are talking about in a room. Just place it under a table in a room and call it. The phone receives the call without ringing and you can listen to what people are saying.

NETWORK MONITOR
There is a hidden menu inside your Nokia phone. If you want to activate it, you'll have to re-program some chips inside of your phone.
  1. Check your software version. You can only continue if you have v4.33, v4.73 or v5.24.
  2. Take apart the phone.
  3. De-solder the EEPROM (ATMEL AT 24C64).
  4. Read out the data with an EEPROM programmer and save it to a file (Backup).
  5. If you have v.33 or v4.73, change the address "03B8" from "00" to "FF".
  6. If you have v5.24 then change the address "0378" from "00" to "FF".
  7. Write the new data to the EEPROM and solder it back to the phone,
  8. Power on your phone and you should have "Netmonitor" enabled.
The Network Monitor gives you the following information.

  • Carrier number
  • MS RX Level in DBM
  • Received signal quality
  • MS TX power level
  • C1 (Path loss criterion, used for cell selection and reselection). The range is -99 to 99.
  • RTL (Radio link timeout).
  • Timeslot
  • Indication of the transmitter status
  • Information on the Network parameters.
  • TMSI (Temporary Mobile Subscriber Identity).
  • Cell identification (Cell ID, Number of cells being used).
  • MCC (Mobile country code)
  • MCN (Mobile network code)
  • LAC (Location area code)
  • Ciphering (On/Off)
  • Hopping (On/Off)
  • DTX (On/Off)
  • Discard cell barred information

CHECK SIM-LOCK
Note - If you bought your Nokia on UK Vodafone or UK Cellnet you do not need to check this because they both transmit on GSM900, and they don't lock the phones. However if you bought your phone on UK Orange or UK One2one your phone may be blocked. The reason is that they both transmitt on GSM1800. To make a call on GSM1800 you need what is known as a "Dual band" phone. A dual band phone is able to transmit on both GSM900 and GSM1800, so they lock the phones so you can't use it with any other network simcard. If you find that your phone is locked you can try different software to unlock it. (we havn't found one that works yet), or you can ask your service provider who will gladly exchange the 10 digit code for about £35.
This is how to check the status of the 4 different locks. Aslo don't try entering the wrong number, because after 3 times it will block the phone for good.

There are 4 different locks on your Nokia phone.
  • COUNTRY-LOCK
  • NETWORK-LOCK
  • PROVIDER-LOCK
  • SIMCARD-LOCK
The code to read out the sim-lock status of your phone is

#PW+(MASTERCODE)+(Y)#
  • # = DOUBLE-CROSS
  • W = PRESS "*" THREE TIMES
  • P = PRESS "*" FOUR TIMES
  • + = PRESS "*" TWO TIMES
  • MASTERCODE = 1234567890
  • Y = NUMBER 1 TO 4
The master code is a secret code. The code has 10 digits, To read out the sim-lock status you can enter every combination you want!
"Y" Shows the status of the network-lock. Here you can enter a number from "1" to "4". The "4" is for the sim-card lock.

SIM-LOCK CHECKS
  • #PW+1234567890+1# = GIVES PROVIDER-LOCK STATUS
  • #PW+1234567890+2# = GIVES NETWORK-LOCK STATUS
  • #PW+1234567890+3# = GIVES COUNTRY-LOCK STATUS
  • #PW+1234567890+4# = GIVES SIM-CARD-LOCK STATUS