Troubleshoot System and Display Issues Flashcards
Overheating
Excessive heat can easily damage the sensitive circuitry of a computer. If a system feels hot to the touch, you should check for overheating issues. Unusual odors, such as a burning smell or smoke, will almost always indicate something (probably the power supply) is overheating. The system should be shut down immediately and the problem investigated. A burning smell may also arise because the case and/or fan vents are clogged with dust.
Diagnosing and correcting overheating issues include the following
—Most systems come with internal temperature sensors that you can check via driver or management software. Use the vendor documentation to confirm that the system is operating within acceptable limits.
—Ensure that the CPU fan is working. Proper cooling is vital to the lifespan and performance of the processor. If the processor is running too hot, it can decrease performance. A processor that is overheating can cause crashes or reboot the machine. Is the fan’s power cable properly connected? Is the fan jammed, clogged, or too small? If a processor upgrade is installed, the fan from the original CPU may not be suitable for the new device.
—Make sure the heat sink is properly fitted. It should be snug against the processor. It might be necessary to clean away old thermal paste and replace it to help the processor run at a lower temperature.
—Always use blanking plates to cover up holes in the back or front of the PC. Holes can disrupt the airflow and decrease the effectiveness of the cooling systems.
—Verify whether the room in which the PC is installed is unusually warm or dusty or whether the PC is positioned near a radiator or in direct sunlight.
Physical damage
Actual physical damage to a computer system is usually caused to peripherals, ports, and cables. Inspect a unit closely for damage to the case;
If a peripheral device does not work, examine the port and the end of the cable closely for bent, broken, or dirty pins and connectors. Examine the length of the cable for damage.
Physical damage: Motherboard
Few problems are actually caused by the motherboard itself, but there are a few things to be aware of.
—The motherboard’s soldered chips and components could be damaged by electrostatic discharge (ESD), electrical spikes, or overheating.
—The pins on integrated connectors can also be damaged by careless insertion of plugs and adapter cards.
If there is physical damage to the motherboard, you will almost certainly need diagnostic software to run tests that confirm whether there is a problem.
Physical damage: connectors
In some cases, errors may be caused by dirt (clean the contacts on connectors) or chip creep, where an adapter works loose from its socket over time, perhaps because of temperature changes.
Physical damage: liquid and dirt
If a system has had liquid spilled on it or if fans or the keyboard are clogged by dust or dirt, there may be visible signs of this.
Physical damage: capacitor
If a component has “blown,” it can leave scorch marks. You could also look for capacitor swelling . The capacitors are barrel-like components that regulate the flow of electricity to the system chips. If they are swollen or bulging or emitting any kind of residue, they could have been damaged or could have failed due to a manufacturing defect.
Troubleshoot Performance Issues: overheating
Check for overheating—If the temperature is too high, the CPU and other components are likely to reduce the performance level to avoid overheating. This is referred to as throttling. Check temperature sensors and fan speeds. If these are high, check whether the computer needs cleaning or if cooling systems need to be replaced or upgraded.
Troubleshoot Performance Issues: misconfigurations
Check for misconfigurations—If the symptom of sluggish performance is found on a new build or after an upgrade or maintenance, verify the compatibility of new components with the motherboard. For example, a memory upgrade might result in the computer no longer using dual-channel mode, reducing performance. Remember to ask the question “What has changed?” when a problem is reported.
Troubleshoot Performance Issues: Verify the problem
A PC has compute, storage, and networking functions. Any of these three may be the source of sluggish performance. If possible, use diagnostic tests to compare performance of the CPU, system memory, fixed disk, and network adapter to known performance baselines. Quantifying what “sluggish” really means and isolating the issue to a particular subsystem will help to identify the probable cause. If the system performance is not sufficient, one or more subsystems can be upgraded.
Troubleshoot Inaccurate System Date/Time
It is important for computers to keep time accurately. To synchronize with other computers on the network or on the Internet. Authentication will not work and utilities such as backup programs and schedulers will be unreliable.
—The real time clock (RTC) is a part of the chipset that keeps track of the calendar date and time. This component runs on battery power when the computer is turned off. The RTC battery is a coin cell lithium battery.
—If the date or time displayed in the system firmware setup program is inaccurate, it can be a sign that the RTC battery is failing.
—Typically, the coin cell type is CR2032, but check the motherboard documentation.
—The RTC battery is also often called the CMOS battery. On older computers, system firmware custom settings were saved to CMOS RAM.
—On current motherboards, configuration data is stored in a non-volatile RAM (NVRAM) chip (flash memory), rather than in CMOS RAM. Flash memory does not require battery backup.
Troubleshoot Missing Video Issues
If no image is displayed on the monitor or projector, first make sure that the display device is plugged in and turned on.
You may also need to use controls on the monitor itself to adjust the image or select the appropriate data source or input channel.
These on-screen display (OSD) menus are operated using buttons on the monitor case. As well as input control, you can usually find settings for brightness, color/contrast, and power saving.
Missing Video Issues: Physical Cabling Issues
If the display is powered on and you can rule out a problem with the input source, check the cable and connectors between the video card and monitor. Make sure the cable is connected securely at both ends and is not loose. Make sure that the cable has not become stretched or crimped. Verify that the cable specification is valid for the application.
To rule out cable problems, use the “known good” technique and substitute with another cable. Alternatively, try the monitor with a different PC to identify whether the problem is with the display unit or with the input source.
Missing Video Issues: Burned-Out-Bulb Issues
Like display monitors, projectors can use different imaging technologies, such as cathode ray tube (CRT), liquid crystal display (LCD), and digital light processing (DLP).
Projector bulbs have a limited lifetime and will often need to be replaced. You might notice the image generated by the projector start to dim. There may also be a bulb health warning indicator light. A completely failed bulb is referred to as a burned-out bulb. You might hear a “pop” from within the bulb and observe scorch marks on the inside or a broken filament.
Missing Video Issues: Intermittent Projector Shutdown Issues
Intermittent projector shutdown is typically caused by overheating. Check that the projector’s fan is working, that the vents are free from dust and are not obstructed, and that the ambient temperature is not too high. If you can rule out overheating, check for loose connector cables and verify that the bulb is secured properly.
Take care when handling projectors. During use, the bulb becomes very hot, and while it is hot, it will be very fragile. Allow a projector to cool completely before attempting to remove it.
