computer buying tips

The desktop computer is not what is once was thanks to the increased popularity of laptops, but it is still a mainstay of personal computing. The value and power offered by a desktop system, as well as the versatility and upgradeability is still unrivaled, making it a great choice for anyone who doesn’t have to move their computer around very often. Today’s desktops come in an incredible assortment of sizes, prices, and performance levels so there is one out there for every buyer.

This desktop computer buying guide will educate you about what to look for when buying your next desktop, on a component by component basis. Desktops are highly customizable so most consumers will able to make the best decision after learning about the parts and then going to a manufacturer’s website or retailer, opposed to narrowing in on a specific model. Today’s computer makers–the Dell’s, Lenovo’s, and HP’s of the world–are extremely competitive with one another so if you have your facts straight, choosing a computer will be easy and fun. After that it’s just about looking for the best price.

Monitor The monitor is your window to what is happening with your computer. A bigger monitor will be better for media watching and gaming, plus will allow for multitasking. A big monitor isn't mandatory, but it's one of the reasons why you get a desktop.

Recommended: 24-inch LCD display Minimum: 22-inch LCD display

Operating System Your operating system is the foundation of your computer's software and something that is being utilized when your computer is on. It's the single most important decision in choosing your computer.

Recommended: Windows 7 Professional, or alternative OS depending on your needs. Minimum: Windows 7 Home Premium

Optical Drive (CD / DVD / Blu-ray) The drive in your computer that plays optical discs... you know, CDs, DVDs, and Blu-ray. Useful for playing video, backing up files, and mandatory for installing some software titles.

Recommended: Single DVD burner, unless if you want Blu-ray Minimum: Single DVD burner

Memory Computer memory, or RAM, is important for system performance and helps when operating demanding software. This isn't the same thing as a hard drive!

Recommended: 6GB DDR3 Minimum: 4GB DDR3

Hard Drive Your desktop computer's hard drive is where all your data is stored. You can have different sized hard drives as well as more than one drive within the computer.

Recommended: 1TB 7200RPM Minimum: 500GB 7200RPM

Video Card The video card is the part of the computer that enables graphics, including games and video. Normal desktop operations (word processing, email, etc.) don't require much graphics power but gaming and HD video requires much more.

Recommended: ATI Radeon HD 5850 Minimum: ATI Radeon HD 4650

CPU The CPU, or processor, is the brain of the computer. It's the primary factor in determining the power of the system.

Recommended: Core i7 920 Minimum: AMD Phenom II X2 550 Black Edition

How to Maintain a Computer System?

How to Maintain a Computer System?

• If you use your computer more than a few hours per day, we suggest you not to turn off your computer at the end of the day. Instead turn off only the monitor to save electricity. Daily power up and down makes the components exposed to high and low temperature cycles that are not good for the life-time of the components, particularly the critical ones such as hard drives, CPU, and memory. The temperature cycle would result in expansion-shrinking cycle for the components. The life-time of electronic components would be increased if they are run at constant temperature with adequate ventilation.
• If your area experiences a few times of power outage per year, it is necessary to use a UPS. Sudden power downs while the system is running may cause severe damage to hard drives.
• A tape backup and a lock to make systems hard to move are worthy investment for critical data.
• Use your hand to touch and feel the cover of your computer at least once a week. The cover should be at room temperature. If it feels warm there may be a problem! Check to make sure that the cooling fans on the power supply and CPU are working properly. Clean the air pathway on the back of the power supply on a regular basis.

Troubleshooting Tips for Cases and Power Supplies

Troubleshooting Tips for Cases and Power Supplies

The most important part of a computer case is its power supply. Unfortunately, it's also the part that has most of the problems for a case. There are two situations when a new power supply may appear dead on arrival (DOA) when they are actually working as described below:

Most cases and power supplies these days are made and tested in China and other Asian countries where 220V electricity is used. Desktop computer power supplies do not switch the power voltage automatically. (Most notebook computers do!) If the factory forgets to turn the manual switch back to 110V for the North American market after testing, the power supply would appear DEAD if you use on a 110V-outlet. Therefore, always check the voltage setting on the back of a new power supply FIRST if it appears dead.

Do not expect an ATX power supply to work by simply plugging the power and turning on the switch. ATX power supplies are soft-switched on and off by the motherboard and BIOS. Therefore, you must plug it to a working motherboard with a working microprocessor, memory and video card to work. If your computer does not turn on after you turn on the power switch, it may not necessarily mean a dead power supply. The problem might be with the motherboard, microprocessor, memory or video card instead. You must examine all these components to isolate the problem.

The most effective technique to tell if a power supply is causing any problem is to use a different one to see if it solves the problem. If everything works with a different power supply, then the new power supply is most likely the troublemaker. Alternatively, you can plug the new power supply to an existing, working computer to see if it works there.

Computer cases are highly modular. If your computer case is still under warranty, you don't have to send the entire case back if only one part of it is defective. For instance, send only the power supply back for exchange if only power supply is dead. The same is true for the face panel and cover. This would save you quite a bit of shipping and sometimes downtime.

More than 70% of all computer problems are related to cabling and connections. Ensure that you all the power plugs are connected firmly, including power connections to your motherboard and all the drives.

Make sure the cooling fan inside the power supply is working all the time. Reach out to feel the fan behind your case often. Clean the fan if necessary. If your case feels warmer than room temperature, check the power supply fan first. Most power supply fans are difficult to replace. You are better off to replace the entire power supply since the new one comes with a brand-new warranty.

Before ATX form factor became popular, the compatibility between a power supply and a specific motherboard could be problematic. However, this problem nowadays does not happen very often any more.

The rest of a case is mostly mechanical. You should be able to find a way to get around most of the problems if you are mechanically inclined.

Troubleshooting - Video

Trouble Shooting Tips after Installing a New Video Card

The following troubleshooting tips may help if you experience problems.

• Check that the card is seated properly in its expansion slot. Some AGP cards have design flaws and are "well-known" to "pop out" during transportation. For PCI cards, if the problem still exists, try a difference PCI expansion slot.
• Ensure the display cable is securely fastened to the card's display connector.
• Make sure that the display and computer are plugged in and receiving power.
• If necessary, disable any built-in graphics capabilities on your motherboard. For more information, see your computer's manual.
• Make sure you selected the appropriate display device and graphics card when you installed your enhanced driver.
• If you have problems during start-up, start your computer in Safe Mode. In Windows 98, press the F8 key when "Starting Windows 98" appears; or, in Windows 98, press and hold the CTRL key until the Windows 98 Startup Menu appears on the screen. Then select the number for Safe Mode, and press Enter.

Troubleshooting - Network

Troubleshooting Tips for a New Network Card

1. If you can't connect to a server or if Windows reports an error after you double-click Network Neighborhood, try the following first:
   • Make sure you're using the drivers that are on the drivers disk that ships with the network interface card (NIC).
   • Make sure the driver is loaded and the protocols are bound. Check the Device Properties list for trouble indicators (an "X" or "!" symbol).
   • Test the NIC adapter with the diagnostic utilities that often came with the driver installation.
   • Check with your LAN administrator - you may need to install additional networking software.
2. If the problem persists, follow these guidelines:
   • Make sure the cable is installed properly. The network cable must be securely attached at both RJ45 connections (adapter and hub). The maximum allowable distance from adapter to hub is 100 meters. If the cable is attached and the distance is within acceptable limits but the problem persists, try a different cable. If you're directly connecting two computers without a hub or switch, use a crossover cable.
   • Try another network cable.
   • Check the LED Lights on the NIC. Before the LEDs can be used for troubleshooting, the network interface card (NIC) must be connected to the network and the network driver must be installed. Most NICs come with LEDs near the connection. The meaning of the LED signals may be different from one manufacturer to the other. Here is a common LED description for 3COM 10/100BT dual speed NIC. Please consult your NIC manual for any difference.

LED	Description	Flashing	Steady (On)	Off
10 LNK	Green: Link integrity	Reversed polarity	Good 10BT connection	No connection between NIC & hub
100 LNK	Green: Link integrity	Reversed polarity	Good 100BT connection	No connection between NIC & hub
ACT	Yellow: Port traffic for either speed	Network traffic present	Heavy network traffic	No traffic

3. The computer hangs when the drivers are loaded.
   • Change the PCI BIOS interrupt settings. See your NIC and system manuals for more details.
   • If you are using EMM386, it must be version 4.49 or newer.
4. Diagnostics pass, but the connection fails or errors occur.
   • At 100BT, use Category 5 wiring and make sure that the network cable is securely attached.
   • At 100BT, connect to a 100BT hub/switch (not 100Base-T4).
   • For NetWare, make sure you specify the correct frame type in your NET.CFG file.
   • Make sure the duplex mode setting on the adapter matches the setting on the switch.
5. The LNK LED doesn't light.
   • Make sure you've loaded the network drivers.
   • Check all connections at the adapter and the hub/switch.
   • Try another port on the hub/switch.
   • Make sure the duplex mode setting on the adapter matches the setting on the hub/switch.
   • Make sure you have the correct type of cable between the adapter and the hub. 100Base-TX requires two pairs. Some hubs require a crossover cable while others require a straight-through cable.
6. The ACT LED doesn't light.
   • Make sure you've loaded the correct network drivers.
   • The network may be idle. Try accessing a server.
   • The adapter isn't transmitting or receiving data. Try another adapter.
   • Make sure you're using two-pair cable for TX wiring.
7. The adapter stopped working without apparent cause.
   • Run the diagnostics program that came with the NIC.
   • Try reseating the NIC in its slot, or try a different slot if necessary.
   • The network driver files may be corrupt or missing. Remove the drivers and then reinstall them.
8. The Wake on LAN (WOL) feature is not working.
   • Make sure the WOL cable is attached and that power is being applied to the computer.
   • Check the BIOS for its WOL setting. Some computers may need to be configured for WOL.
   • Make sure the network cable is fully attached to the adapter.
9. Crossover cable troubleshooting tips. When you work with network cabling, concentrators (hubs or switch), and NICs from different venders, it is possible to connect everything and still have no communication between file servers and workstations. 
   When there are several unknown variables, it is difficult to determine which component is broken. Use these tips to isolate the problem.
   • Determine whether your equipment complies with the 10Base-T or 100Base-TX standard. This is particularly important for hubs and switches.
   • Connect a straight-through cable from the PC to the hub. The hub performs an internal crossover so that the signal can go from TD+ to RD+ and TD- to RD- (see How to Make Network Cables). When you look at an RJ-45 connector from the front, pin 1 is identified on the left-hand side when the metal contacts are facing up.
   • Make sure that the TD+ and TD- wires are twisted together , and that the RD+ and RD- wires are twisted together. Using wires from opposing pairs can cause signals to be lost. For a 100Base-TX cable, pins #1 and #2 , and #3 and #6 must be on the same twisted strand.
   • 
     
10. When there is doubt whether a hub is performing correctly, or if the impedance settings are in question, a crossover cable can help you isolate the failing component:
    • Connect a file server and a client PC back to back with a crossover cable to verify that the NIC and network operating system are properly configured.
    • To make a crossover cable, simple connect TD+ to RD+ and TD- to RD-. The cable performs the crossover that is usually performed by the hub. Make sure that two twisted-pair wires are used. If the file server and client PC function together as a small network, then either the existing cabling or the hub is the problem.
    • If there is a proper crossover, the appropriate LED comes on. If there is a straight-through connection, the LED does not light. A blinking LED indicates that there is a polarity mismatch (that is, TD+ to RD- instead of TD+ to RD+).

Troubleshooting - Motherboard

Troubleshooting Tips for a New Motherboard

More than 70% of all computer problems are related to cabling and connections. Ensure all cables are connected and connected firmly. IDE and floppy ribbon cables and power cables can often go loose. Ensure microprocessor, memory modules, and adapters such as video card are inserted correctly and didn't "pop-up" due to vibration.

System has no power at all. Power light does not illuminate, fan inside the power supply does not turn on, and indicator light on keyboard does not turn on.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Power cable is unplugged.	Visually inspect power cable.	Make sure power cable is securely plugged in.
Defective power cable.	Visual inspection, try another cable.	Replace cable.
Power supply failure.	Power cable and wall socket are OK, but system is still dead.	Contact technical support
Faulty wall outlet;circuit breaker or fuse blown.	Plug device into socket know to work and test.	Use different socket, repair outlet, reset circuit breaker or replace fuse.

System inoperative. Keyboard lights are on, power indicator lights are lit, and hard drive is spinning.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Expansion card is partially dislodged from expansion slot on the motherboard.	Turn off computer. Take cover off system unit. Check all expansion cards to ensure they are securely seated in slots.	Using even pressure on both ends of the expansion card, press down firmly on expansion card.
Defective floppy disk drive or tape drive.	Turn system off. Disconnect the cables from one of the floppy drives. Turn on the system, check to see if the keyboard operates normally. Repeat until you have located defective unit.	Contact Technical Support.
Defective expansion card.	Turn computer off. Remove an expansion card.	Make sure expansion card is secure in expansion socket.

System does not boot from hard disk drive, can be booted from floppy disk drive.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Connector between hard drive and system board unplugged.	When attempting to run the FDISK utility described in the HARD DISK section of the manual you get a message, INVALID DRIVE SPECIFICATION.	Check cable running form disk to disk controller on the board. Make sure both ends are securely plugged in; check the drive type in the Standard CMOS Setup (in your motherboard manual).
Damaged Hard Disk or Disk Controller.	Format hard disk; if unable to do so, the hard disk may be defective.	Contact Technical Support.
Hard Disk directory or FAT is scrambled.	Run the FDISK program, format the hard drive(See HARD DRIVE section of manual). Copy your backup data back onto hard drive.	Backing up the hard drive is extremely important. All Hard Disks are capable of breaking down at any time.

System only boots from Floppy Disk. Hard Disk can be read and applications can be used, but booting from Hard Disk is impossible.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Hard Disk boot program has been destroyed.	A number of causes could be behind this.	Back up data and applications files. Reformat the Hard Drive as described in the Hard Drive section of the manual. Re-install applications and data using backup disks.

Error message reading "SECTOR NOT FOUND" or other error messages indication certain data is not allowed to be retrieved.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
A number of causes could be behind this.	Use a file by file backup instead of an image backup to backup the Hard Disk.	Back up any salvageable data. Then do a low level format, partition, and high level format of the hard drive( see Hard Disk section of your manual for instructions). Re-install all saved data when completed.

Disk formatted on IBM PS/2 will not operate with this system.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
The IBM PS/2 uses a different format than other computers.	IBM PS/2 disk format will not work in an AT type computer.	Format disk in the AT type computer insert disk into the IBM PS/2 and copy the files you wish.

After install an expansion card (network card, tape drive card, etc.) the system no longer works properly.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
No power to monitor.	All or part of the system may be inoperable. The new card may work but a mouse or COM port may not work.	Change the interrupt or RAM address on the new expansion card. See the documentation that came with the new card in order to change pin settings. many expansion devices come with proprietary software that will assist you in doing this.

Screen message says "Invalid Configuration" or "CMOS Failure."

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Incorrect information entered into the configuration (setup) program.	Check the configuration program. Replace any incorrect information.	Review system's equipment. Make sure correct information is in setup.

Screen is blank.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
No power to monitor.	Power connectors may be loose or not plugged in.	Check the power connectors to monitor and to system. Make sure monitor is connected to display card, change I/O address on network card if applicable.
Monitor not connected to computer.		See instructions above.
Network card I/O address conflict.		See instructions above.

System does not boot from hard disk drive, can be booted from floppy disk drive.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Connector between hard drive and system board unplugged.	When attempting to run the FDISK utility described in the HARD DISK section of the manual you get a message, INVALID DRIVE SPECIFICATION.	Check cable running form disk to disk controller on the board. Make sure both ends are securely plugged in; check the drive type in the Standard CMOS Setup (in your

Problem

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Memory problem, display card jumpers not set correctly.		Reboot computer. Re-install memory, make sure that all memory modules are installed in correct sockets. Check jumper and switch settings on display card. See display card section for information of settings.
Computer virus.		Use anti-virus programs (McAfee/PC-cillin, E-port, etc) to detect and clean viruses.

Screen goes blank periodically.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Screen saver is enabled.		Disable screen saver.

Keyboard failure.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Keyboard is disconnected.		Reconnect keyboard. Check keys again, if no improvement, replace keyboard.

No color on screen.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Faulty Monitor.		If possible, connect monitor to another system. If no color, replace monitor.
CMOS incorrectly set up.		Call technical support.

Floppy drive lights stays on.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Floppy Drive cable not connected correctly.		Reconnect floppy cable making sure PIN1 on the Floppy Drive corresponds with PIN1 on floppy cable connector.

Error reading drive A:

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Bad floppy disk.		Try new floppy disk.
Floppy disk not formatted		Format floppy disk(type ENTER)

C: drive failure.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
SETUP program does not have correct information.		Boot from drive A: using DOS system disk. Input correct information to SETUP program.
Hard Drive cable not connected properly.		Check Hard drive cable.

Cannot boot system after installing second hard drive.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Master/Slave jumpers not set correctly.		Set master /Slave jumpers correctly.
Hard Drives not compatible / different manufacturers.		Run SETUP program and select correct drive types. Call drive manufactures for compatibility with other drives.

Missing operating system on hard drive.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
CMOS setup has been changed.		Run setup and select correct drive type.

Certain keys do not function.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Keys jammed or defective.		Replace keyboard.

Keyboard is locked, no keys function.

PROBABLE CAUSE	DIAGNOSIS	SOLUTION
Keyboard is locked.		Unlock keyboard