With over two thousand articles here about Macs and their problems, it can be tricky to know where to look first. Here’s a selection of starting points for troubleshooting and solving issues.

Troubleshooting macOS: Observation and the log
Pick your Panacea: how to select a generic fix
Prepare your Mac for service/repair, and restore it later

M1 Macs (Apple Silicon)

Introducing your new M1 Mac
Startup modes for M1 Macs
Inside M1 Macs: Time and logs
Which firmware should your Mac be using? (version 5) – for Big Sur
Boot volume layout
The non-Universal binary: a cautionary tale
Apple Silicon Macs will require signed code
Magic, lipo and testing for Universal binaries
Tuning Apple Silicon will be complex at first

Crashes, freezing, panics

Diagnosing an abnormal startup: what that screen means
Did your Mac crash, freeze or panic?
Understanding ‘crashes’ and kernel panics
How to recognise and diagnose kernel panics
Reading a Panic Log in Catalina
How a kernel zone memory leak can panic macOS
WindowServer-GPU crash: different from a kernel panic
Tackling sleep and wake problems
Diagnosing a Mac which can’t complete booting
What to do when a process is using excessive CPU

Problems after system updates

What to do when a macOS update goes wrong (macOS 10.13-11.0)
The universal panacea for macOS problems: install the Combo updater
A plain guide to Mac firmware and its problems
Reset and maintain your SMC and NVRAM

Crash recovery and disk problems

Making sense of Disk Utility and disk structure in macOS 10.13-10.15
Should you trust Disk Utility’s First Aid or fsck?
Recovering from a hard crash – when your startup drive is missing or damaged
Monitoring SSD wear and ageing
Checking your drives with DriveDx
Q&A – Dead Mac recovery – recovering files from a dead Mac
S.M.A.R.T.ypants – hard drive failure detection

App problems – preference settings

Preference settings: where to find them in Mojave
Global defaults in macOS Mojave
Working safely and effectively with preferences in Mojave
Unsticking stuck preference settings

Keychain problems

Tackling keychain problems with KeychainCheck 2, now a Universal App
Why do I have to keep entering my keychain password in Sierra?
How to repair your keychain by making a fresh one

Time Machine problems

Time Machine 17: Using utilities to solve problems
Time Machine: 1 How it works, or fails to
Time Machine: 2 What it writes in the log
Time Machine: 3 Analysing automatic backups
Time Machine: 4 Problems with backups
Time Machine: 5 Changing Macs and more
Time Machine: 6 Networked storage
Time Machine: 7 Checking logs using Ulbow
Time Machine: 8 Preventing problems
Time Machine: 9 Inside backup support files
Time Machine: 10 Tools
Time Machine: 11 tmutil
Time Machine 12: Backups that never complete
Time Machine 13: Backups and versions
Time Machine 14: Diagnosing and working around slow backups
Checking backup transfer rates using T2M2 version 1.13
Time Machine 15: Large files including VMs
Time Machine 16: Reading a normal backup in Catalina using Mints
How to check the integrity of files in a Time Machine backup
What to do when T2M2 or another log-based app returns an error

Logs – Sierra and later

Use Ulbow on Sierra and later
macOS Unified log: 1 why, what and how
macOS Unified log: 2 content and extraction
macOS Unified log: 3 finding your way
Locating a problem in the log using Ulbow 1.1b3
Time Machine: 7 Checking logs using Ulbow
When did my Mac last start up, and why? An exploration with Ulbow
Mac shutdown and sleep cause codes
How to reveal ‘private’ messages in the log

Logs – El Capitan and earlier

Log race – understanding and using Console’s logs
Reading logs: shutdown and startup
Reading logs: waking from sleep and backing up
Getting El Capitan to run clean – using Console and guesswork to stop repeated service crashing
Service with a Smile – advanced troubleshooting of services and the startup process

Privacy protection

A Guide to Catalina’s Privacy Protection: 1 Principles and structure
A Guide to Catalina’s Privacy Protection: 2 Controlling privacy settings
A Guide to Catalina’s Privacy Protection: 3 New protected locations
Diagnosing privacy protection problems in Catalina
A Guide to Catalina’s Privacy Protection: 4 tccutil
A Guide to Catalina’s Privacy Protection: 5 Location

Networks

Small Networks Without Big Headaches – setting up and diagnosing a small network
My email is broken – how to diagnose and fix mail problems
The medium of the message – email clients and types

iCloud and cloud services

A break in the clouds: when cloud services won’t work – including links to service status for iCloud, Adobe CC, etc.
Testing iCloud using Cirrus
What to do when your account might have been compromised
Which extended attributes does iCloud preserve, and which get stripped?

Generic approaches

Did someone forget their password? Getting access to a locked Mac
Solutions for macOS Monterey and Big Sur
Pick your Panacea: how to select a generic fix
My Mac don’t work – troubleshooting tools and techniques
How to tell whether a problem is in your Home folder
Memory Lane: Grokking memory problems in Activity Monitor
Generic troubleshooting: how to fix something that doesn’t work

Tackling the serious and insoluble

Reviving the hopeless Mac: what to try before visiting the Genius Bar
Prepare your Mac for service/repair, and restore it later

Useful references

Conventions and Standards for Mac Articles
How to get an old version of macOS, OS X and Xcode
Which startup mode?
Startup and shutdown key combinations for macOS Sierra
Reset and maintain your SMC and NVRAM
Firmware fundamentals
A plain guide to Mac firmware and its problems
Which EFI firmware should your Mac be using? (version 4) – for Catalina
Which EFI firmware should your Mac be using? (version 3) – for Sierra, High Sierra and Mojave
Which EFI firmware should your Mac be using? (version 2) – for El Capitan and earlier
Safe Booting in Catalina has changed
My Mac only runs properly in Safe mode
Which Recovery Mode?
Recovery mode and its tools
Hardware diagnostics
More About This Mac: where to find that UUID, MAC address, etc.
Boot volume layout
macOS Mojave Boot Volume Layout
How should you clean re-install Catalina?
How clean re-installs change in Catalina
How to check quarantine, 64-bit, signature, and notarization for almost anything
A user’s guide to code signatures and notarization
What happens when you run an app in Catalina?
How Catalina handles app first run
Will Gatekeeper let me run that app in Catalina?
What happens when you double-click a document? Processes, problems and solutions
Copy, move and clone files in APFS, a primer
Apple has changed resetting permissions again
Why are my Mac’s fans running at full blast?
Caring for well-washed hands
Disinfecting your Mac and devices
How to clean Macs and other Apple hardware

Further details

Full categorised listing of Mac articles here.

Free tools available

Here is the downloadable PDF version with links to all the product pages:
AppSelectionChart