PC Construction and Maintenance Week 10 General Troubleshooting

Mental state very important to success of troubleshooting Often need to ensure that problem is diagnosed before attempting solution Need to take time to think carefully about the problem If cant be solved, switch computer off and do something else. Try again later

General Troubleshooting Keep an open mind regarding the problem Dont be stubborn, change direction if things are not working out Always be prepared to learn more from other people Use the Internet to learn Two heads are always better than one A fresh perspective can often solve the problem

Diagnosing a Problem Ask yourself why a problem could be occurring Try to follow a logical chain of reasoning Get to the root cause of the problem Eliminate possible causes, one at a time Try to avoid knee-jerk reaction to fixing a problem

Diagnosing a Problem Change only one thing at a time Be very observant Be reluctant to discount possible causes of problems, even if they seem unrelated There is no substitution for experience Can never have enough trouble shooting experience

Troubleshooting tips It is much easier to troubleshoot if you have a usable stockpile of spare parts You dont have to buy these, you just need to borrow them from another machine while you are troubleshooting Without having access to a spare stockpile, it can be very difficult to troubleshoot problems Assuming you know that the spare parts work, you can use them to eliminate problems

The Log Book When Troubleshooting, or learning about PC hardware, It is a very good idea to write things down Much later, you can solve a recurring problem that you would otherwise forgotten how to solve Some solution procedures can be complex and need to be written down somewhere

Types of Problem Two main classes of problem – Repeatable and Intermittent Intermittent problems are much harder to deal with You can never really be sure that an intermittent problem has been solved With repeatable problems, you often can have some clues into finding the cause of the problem

Dealing With Intermittent Problems Sometimes you just have to be patient, by changing a single thing and then waiting to see if a problem comes up again Sometimes, this can be frustrating, so occasionally need to take drastic action In that case, we would like to make an educated guess to whether the problem is software or hardware

Software of Hardware? Some problems may first seem like hardware, but can often be caused by software misconfigurations Sometimes, removing or replacing a device from a machine may fix the machine. That does not imply that the device has a fault however Some hardware configurations are just incopatible

Top 10 Hardware Problems Failing hard drive due to age, dust or motherboard/CPU upgrade Overheating of components due to insufficient cooling Overloading of PSU caused by having too many internal peripheral devices Floppy drive failure due to dust, dirt, misaligned heads, or insertion of damaged disk CD-ROM drive problems due to misalignment of laser or dust etc..

Top 10 Hardware Problems Loose chips and cables esp. CPU and BIOS chip Wrong type of RAM for system Failed RAM and/or failed motherboard cache RAM Processor faults due to (sometimes accidental) overclocking, or incorrect CPU core voltage Loose peripheral cards Bent connector pins

Top 10 Software Problems Viruses Out of date/incompatible device drivers IRQ conflicts caused by BIOS/OS allocation of resources Old operating system on new machine System unstable due to application installs (e.g. DLL hell)

Top 10 Software Problems File system inconsistencies caused by not shutting down properly, or broken software Out of date BIOS firmware Incorrect regional settings Incorrect display settings, e.g. refresh rate out of range Irreversible inconsistencies in the system registry/configuration Incorrect BIOS settings

Solving the problems After eliminating the most likely causes, we often still cant find out what is causing the problem When we finally hit a brick wall, and exhaust our knowledge we may have to accept that the cause may never be known We can then look into re-installing windows

Re-installing windows We have two choices, overlay an install, or perform a fresh install In both cases, it is desirable to preserve all of our data files A fresh install is the most likely to fix any remaining software problems Fresh install takes half an hour to perform, but a day to re-install the majority of applications

Tricks of the trade for a fresh install (95/98/ME) You do not need to remove a single file from the existing Windows installation We just need to shut down to DOS mode, or boot from a DOS floppy CD into C:\WINDOWS, and rename the file win.com to win.old by typing REN WIN.COM WIN.OLD Change back to the top level folder, and rename the windows folder to windows.old by typing REN WINDOWS WINDOWS.OLD

Recovering old Applications Before we reinstall Windows, we often want to backup the system registry The registry stores Application-specific and System specific configuration data We use the regedit command from the start menu under windows to export this file to a plain text file Later, we may need to restore fragments of the registry in order to re-install old applications for which we have lost/misplaced the original disks