Input/ Output port enables you to connect hardware devices such as the keyboard, flash drives, mouse, printer and scanners to the system. It is the entry and exit point for data from the system. A port is used to connect the system and a device together, using a connecting cable, so that they can communicate together. The different ports available are usually located at the back of the system case or they may also be located at the front side of the system case.
Types of ports:
The ports have different shapes and size and so before purchasing a device you must check if you can attach a device to the system using the port available on the system. Based on this the ports are classified into different types:
- Serial ports: A serial port is like a single lane road that sends and receives one bit of data at a time. Thus, eight bits of data in one byte travel one bit at a time, one behind the other. The serial port connector is also known as the communication or Com port and can have 9 or 25 pins. A serial port is used to connect devices such as the mouse, plotters, PDA docking devices, bar code readers, scales, device control circuits and external modems to the system.
- Parallel ports: A parallel port is like an eight lane road that transmits eight bits of data at a time. It is like eight cars moving on a wide road side by side. The parallel port connector has 25 pins to connect devices such as printers, scanners, external hard drives and tape drive backup devices.
- PS/2 ports: The PS/2 port is used to connect the keyboard and mouse to the system. The ports are available in a colour that matches the colour of the plug connecting the mouse and keyboard. This port uses 6 pins to connect the devices.
- Universal Serial Bus (USB) Ports: The USB port is a rectangular port that is used to connect a variety of devices to the system. The USB port also supplies power to the device such as web camera, if the device does not use an external power source. To use the USB device you must just plug the device into the USB port, as most USB device offer Plug-and-play support. You must install the USB drivers before using the USB port.
- Infrared ports: Devices use the infrared ports to communicate with the system without using wires. The devices send out infrared signals that enter the system through this port.
- Bluetooth ports: Bluetooth is technology which allows wireless communication between devices within a ranged distance. A Bluetooth adapter is required for the computer and a Bluetooth compatible device to communicate through Bluetooth
- IEEE 1394 BUS: The Institute of Electrical & Electronics Engineering (IEEE) 1394 is a standard for the external bus that enables fast and high serial data transfer between the system and the connected devices. The IEEE can transfer data at the speed of about 400 Mbps.
Troubleshooting problems with the I/O ports:
Problems with the I/O ports result in errors being displayed while using the device, the operating system may crash while using the device. The device may also not function if the device IRQ line conflicts with another device. A hardware device may not work if there is some problem with the I/O port, the system or with the device itself.
- Check if the device is properly connected to the port.
- Remove the device from the port and connect it to another vacant port.
- Scan the system for viruses.
- Uninstall and reinstall the device drivers.
- Check if the card for the port is properly attached to the motherboard.
- In the BIOS settings, check if that particular port is enabled.
- Try attaching the device to a different system to check if the device is functioning properly, if the device works on the other system then the port is spoilt.
- Troubleshoot the device.
Digital Versatile Disk (DVD) is a form of digital storage. DVD is used to store music, video, games and multimedia applications. DVD is similar to a CD in appearance and structure. It offers high capacity and better quality as compared to the CD. The storage capacity of DVD is 7 times that of CD.
Working of DVD
Tracking system of DVD player consists of tracking motor and spindle motor. Tracking system is responsible for proper alignment of data tracks on the DVD and the laser beam. The tracking motor moves the laser assembly to and from the centre of the DVD. The spindle motor spins the DVD at a rate that allows for constant reading of data by the laser beam. DVD drive reads the data from DVDs with the help of a laser assembly, which focuses the laser beam on the DVD. The laser beam reads the data on the DVD that is stored in the form of microscopic pits. The laser beam focuses on the reflecting layer of the DVD. In case of the single layer DVD’s, laser passes through the layer and to the reflecting layer underneath it. If the DVD is dual layered, it has to focus on the inner reflective layer by passing through the two layers and then to the reflective layer.
The laser is reflected off the reflective layer onto a photosensitive receptor. The DVD track has data encoded in it in the form of pits, and the areas on the track that do not contain data are flat and smooth. The laser is reflected in a different manner from the smooth area as compared to the pits. The photosensitive receptor studies the reflected signal for changes in the reflection. The device that interprets the reflection changes and reads them as bits of data. The DVD drive has to convert the data read from the DVD into 1 or 0 bits. These bits of data are then sent to Digital to Analog Converter (DAC), if the data is intended for a device that uses analog data. If the device is digital, the data can be directly passed to the device.
Troubleshooting the DVD drive:
- There is no power in an internal DVD drive:
- Internal DVD drives receive power from the computer supply. If the other parts of the computer are problem-free, it means that the power supply is not at fault.
- Replace the connector of the DVD drive to the power supply. If the DVD drive does not start working even after the connector is replaced, the drive is faulty.
- The tray of the internal DVD drive will not open:
- Restart the computer. Then try to open the tray.
- If the tray does not open after restarting, check the BIOS settings to see if the computer recognizes the drive.
- Try the manual eject button on the DVD drive.
- Shutdown and unplug the computer. Use a small device like a paper clip to inset in the pin hole on the front of the DVD drive. Try to open the tray a little with the help of the paper clip, and the n open with your fingers.
- DVD drive runs lowly:
- Check the cache size in the Performance tab of the System Properties. Select the quad speed setting.
- Move the drive to the secondary controller if possible.
- Check the drive specification and use auto detect in BIOS for the best results.
- Install the appropriate drivers for the motherboard’s chipset and OS in use.
- Proper installation and configuration of the DVD drive is very important for the proper working of the DVD drive.
- DVD drives and burners have speed listings that indicate the speed of the drive as compared to the DVD standards.
- A combo drive can play DVD’s and record on CD’s.
- Troubleshooting the DVD drive can eliminate most of the problems of the DVD drive.
- DVD drives can experience problems due to power supply failures, computer problems, etc.
Troubleshooting the Motherboard
If the system crashes repeatedly, it is possible due to motherboard failure. However actual motherboard failure is rare. It is possible that some other problems like loose connections, power failure or overheating may cause system failure.
- Turn off the system and remove the power cord.
- Check connections on the motherboard.
- If you have made any changes to the BIOS settings, restore them to the default value.
- Ensure that the motherboard is not touching the system case or the drive tray.
- Check whether there are any cross connections between wires.
- Wear an anti static wristband.
- Place the removed components on antistatic package.
Instability in a new system:
A newly assembled system may show problems like frequent error messages and problems while starting up. These problems can be caused by a variety of reasons like loose connections or incorrect settings. Some of the problems may also be caused due to motherboard.
- Check all connections and cables on the motherboard. The connections must be tight and placed properly.
- Ensure that the motherboard with the CPU, video card and the memory is properly connected to the power supply.
- Check the system temperature and ensure that the heat sink and fan are working properly.
- Check if the power supply is loaded with more devices and components than it can handle. If you have upgraded your system or added a device, the power supply must be able to handle it.
- The system memory may have failed. Check the system memory and ensure it is connected and configured properly. Also check if the memory is compatible with the motherboard.
- Check the jumper settings on the motherboard. Inspect the CPU for any problems.
- Check the BIOS settings and ensure if they are correct. If possible set them as default.
- Inspect the expansion cards on the motherboard for proper correction or configuration.
- Ensure that the hard disk drives have proper jumper settings.
- Check the IRQ settings of the system for any conflicts that can arise during system assembly or addition of new hardware.
- If your cache is corrupt or incompatible, it may lead to motherboard problems. Disable cache in BIOS. If the system works properly, then the cache was faulty.
- If the system does not work properly, check whether the cache is properly installed.
System does not start though fans are working:
In some cases, you may not be able to access drives and the video may also not work. If the system does not start up, but the system fans work fine, it is mostly either a motherboard or CPU problem.
- Remove the CPU and reseat the Motherboard.
- Check the seating of the CPU on the motherboard and ensure that it is locked down.
- Ensure that the motherboard power supply is properly connected.
- Check all the ribbon cables to see that they are connected to the appropriate drives and they are oriented properly.
- Reset the BIOS settings to default. Try the safe booting procedures with power up defaults by referring to the motherboard manual.
- If the system does not start up, the memory, CPU or the motherboard are faulty.
- Remove any additional memory and try starting with minimum memory. Then swap the memory and try starting the system. If the system starts with either of the memories than the other memory is faulty.
- Check all jumpers and connections on the motherboard. Check the motherboard expansion slots for metal fragments.
- Replace the CPU on the motherboard, if the system works the CPU is faulty.
- If the system does not work with the new CPU, try placing the CPU on another motherboard. If it works then, your motherboard is faulty.
When switched ON, the system only beeps or shows POST error:
- Check post messages and correct the problem if possible.
- Check for perfect connection of socketed chips such as memory modules, BIOS or keyboard controller, CPU etc.
- Temporarily remove the network cards and other PCI cards from the motherboard.
- If the problem is solved then replace cards one by one and each time check for where actually fault lies.
- Remove and reset all essential expansion cards and check the interconnecting cables.
- If the system does not function than replace the Motherboard.