Computer Troubleshooting

See Wired Connection Interface for ethernet related tools
See Wireless Connection Interface for Wi-Fi and other Wireless Utilities
See Computer Network for software utilities
Safety
1. Anti-static wrist band
2. Class C Fire extinguisher (for electrical fires) - know location
General repair kit tools
1. Computer repair kit (various models)
  1. Includes screw driver set (e.g. ProTech)
    1. Includes phillips head, jewelers set, Torx security driver
  2. Demagnetizing block
2. Universal, All-in-one multi-card readers (e.g. SD, micro-SD, mini-SD)
3. Multimeter (voltage, current resistance)
4. External drive enclosure (laptop and desktop sizes with USB and SATA interfaces)
  1. Allows removal of internal drive and clone to another drive
5. Network Testing
  1. See Wired Connection Interface
  2. Tone Generator and Cable Tracer Probe
  3. Cable Tester (e.g. Fluke Networks)
  4. Loopback Plug
Specific hardware testing tools (devices used by computer repair shops)
1. Power Supply Tester
2. RAM Tester (expensive)
3. Storage device Tester (e.g. hard disk)
  1. Clone problematic hard disk and work with the data on the cloned device
4. Power On Self Test (POST) Card (inexpensive)
  1. Allows testing of motherboard without other components installed
  2. https://en.wikipedia.org/wiki/POST_card

System Tools
1. Microsoft Desktop Optimization Pack - Diagnostic and Recovery Toolset (DART Tools)
  1. Suite of diagnostic tools available to Microsoft enterprise customers
  2. https://technet.microsoft.com/en-us/library/jj680675(v=vs.85).aspx
2. Hiren's BootCD
  1. Boot environment allowing for troubleshooting
  2. Use only the freeware and shareware integrated tools
Testing Firewall
1. Shields Up
  1. https://www.grc.com/shieldsup
  2. Tests ports as well as UPnP settings
Startup Utilities
1. MsConfig
  1. Check startup applications (any unsigned, potential malware?)
  2. Set-up diagnostic reboot (and also allow more time to press F8 on boot-up)
2. Services.msc
  1. Review all services
3. Device Manager (DevMgmt.msc)
4. Task manager
5. Autoruns
  1. Microsoft utility (download from Technet)
  2. Visualize all start-ups and plug-ins on system
6. Windows Re-boot setting in windows
  1. From the start screen, click the power button, then Shift-Click the restart button
  2. Click Troubleshoot => Advanced Options => Start-up Settings => Restart
7. Windows Safe Mode (safest without networking)
  1. Used for evaluating a malware infected system, troubleshooting video problems

Identify the problem (from affected end-users)
1. Specific problem (circumstances to reproduce)
2. Onset of problem and what system changes preceded the problem
Establish the probable cause (root cause analysis)
1. Consider simple layer 1 problems (e.g. ethernet cables and connections)
2. Consider hardware versus software issue
Test the theory (reproduce the problem)
1. Consider split-half approach (e.g. test hardware in another PC and if works, then problem is with software)
2. Methodically test one item at a time (instead of shotgun approach)
Establish plan and implement solution
1. Keep in mind customer service agreements and established maintenance windows when planning disruptive solutions
2. Predict downtime to allow users to plan appropriately
3. Make only one change at a time
4. Escalate as needed to a higher level
Verify fix and take preventive measures
1. Confirm the system work on both your own test as well as for end-user
Document findings, actions taken and outcomes
1. Often recorded in trouble ticket database
References
1. Warner (2015) CompTIA A+, Pluralsight