Mac Maintenance: The Complete Auckland Guide to MacBooks and iMacs

Quick Summary

A slow, ageing, or damaged Mac is rarely a reason to give up on it. Most slowdowns trace back to a handful of fixable causes — background processes, a nearly-full drive, an outdated macOS version, or dust affecting cooling — and most physical issues, including cracked MacBook screens, have a clear repair path even if the Mac itself can’t be upgraded internally the way a Windows laptop can. The two things genuinely worth knowing upfront: most Macs made since around 2012 have RAM and storage soldered in place, so “just add more RAM” usually isn’t an option, and a MacBook’s screen is a single fused assembly, so screen damage almost always means replacing the whole lid rather than just the glass.

Why Macs Need Maintenance Too

“Macs don’t get viruses” and “Macs don’t slow down” are two of the most persistent myths in personal computing, and neither is true. Macs are absolutely capable of running into malware, scareware, and the same kind of gradual slowdown as any other computer — they simply experience it differently to Windows machines, which is exactly what makes generic “speed up your computer” advice a poor fit for a Mac. This guide covers both MacBooks and iMacs, calling out where the two genuinely diverge — battery health and screen design are completely different conversations between a portable Mac and a stationary one.

Speeding Up a Slow Mac (MacBook or iMac)

Check Activity Monitor for any single process using an unusually high share of CPU, memory, or disk — this is the Mac equivalent of Windows Task Manager and the fastest way to spot a runaway app.
Give Spotlight time after a major macOS update. It’s completely normal for a Mac to feel sluggish for a day or so after a big update while Spotlight quietly re-indexes your files in the background. This isn’t a fault — it resolves itself.
Review Login Items in System Settings, which controls what launches automatically when you log in, the same way startup apps do on Windows.
Check for “Other” storage bloat. The storage breakdown in System Settings often shows a large “Other” category — old caches, app support files, and forgotten downloads that are easy to overlook when trying to free up space.
Be cautious with old Intel-only apps on Apple Silicon Macs. Software that hasn’t been updated for Apple Silicon runs through Rosetta translation, which is noticeably slower than a native app doing the same job.
Watch for Time Machine running in the background. A scheduled backup can visibly slow things down while it’s actively running, particularly on older hardware.
Know what can and can’t be upgraded. Most MacBooks since around 2012, and most iMacs since around 2019, have RAM soldered to the logic board — fixed at the time of purchase. Some older iMacs (roughly 2012–2019, depending on model) have a small access door specifically for user RAM upgrades, which is one of the clearer differences between the two product lines worth checking before assuming an upgrade is possible.

macOS Updates and Support Windows

Apple typically supports a given Mac model with major macOS updates for roughly seven to eight years from release, after which it stops receiving new annual macOS versions — though it may continue receiving smaller security patches for a period after that. Knowing where your specific model sits in that timeline matters for two reasons: a Mac running the newest macOS it’s eligible for will often feel slower than it did on an earlier version, simply because each new macOS release expects more from the hardware; and once a model stops receiving any updates at all, it’s accumulating the same kind of unpatched security risk discussed in our Cybersecurity & Data Protection Guide. Apple’s own coverage lookup tool (checkcoverage.apple.com) lets you check a Mac’s exact model and support status using its serial number.

Apple also issues smaller Rapid Security Response updates between full macOS versions for urgent fixes — worth installing promptly when one appears, even outside your usual update routine.

Storage and Backup Management

Use Optimised Storage (in System Settings, under Apple ID/iCloud) to automatically offload older files and photos to iCloud while keeping smaller local placeholders, freeing up space without deleting anything permanently.
Set up Time Machine properly rather than relying on it as an afterthought — an external drive (or network volume) dedicated to Time Machine, backing up regularly rather than only occasionally, is the most Mac-native way to maintain the offsite backup principle covered in our Cloud Storage Guide.
Periodically check what’s actually using your storage, it’s a common source of unnecessary clutter that doesn’t show up under any obvious file type.

Battery Health (MacBook Only)

This section doesn’t apply to an iMac, since it runs on mains power — but it’s one of the most important maintenance topics for any MacBook.

Check Battery Health in System Settings periodically. Apple’s built-in battery health tools show cycle count and overall condition, and will flag if the battery has degraded to the point of needing service.
Use optimised/managed charging where available. Apple’s charging management features learn your daily routine and slow the final stage of charging when the MacBook is plugged in for long periods, which reduces long-term battery wear compared with sitting at 100% continuously.
Treat a swollen battery as a safety issue, not just a performance one. A battery that’s visibly puffed, causing the trackpad to lift or the bottom case to bulge, should be stopped from charging and assessed professionally as soon as possible — this is a genuine fire risk, not just a sign of reduced battery life.

Thermal Care and Cleaning

We cover the general principles of dust, humidity, and cleaning safely in our Computer Cleaning Guide — a few points specific to Macs:

Most modern MacBooks are sealed, unibody designs, which makes internal dust removal a job for a technician rather than a DIY project, unlike many Windows laptops with more accessible vents.
Older iMacs are generally more accessible for an internal clean, given their larger, more open case design compared with a laptop.
The MacBook Air is fanless, which is fine for everyday use but means it throttles itself under sustained heavy workloads with no fan to help dissipate the extra heat — that’s expected behaviour by design, not a fault.
Older Intel MacBook Pros are more prone to thermal issues as they age, partly because thermal paste between the processor and heatsink degrades over years of use, reducing cooling efficiency even with a clean fan.

Repairability and Upgrades

It’s worth being upfront about this rather than letting it be a surprise at quote time: most Macs from roughly the last decade are simply not designed to be opened and upgraded by the owner. RAM and storage are typically soldered directly to the logic board on modern MacBooks and iMacs, which means the configuration chosen at purchase is usually the configuration for the life of the machine. The clearest exception is a window of older iMacs (roughly 2012–2019, varying by model) that included a small user-accessible door specifically for RAM upgrades — if you have one of these, it’s one of the few genuinely cost-effective upgrades available on an ageing iMac.

Screen Damage and Replacement

Screen damage is one of the most common reasons Mac owners come to us, and it plays out very differently for a MacBook than an iMac.

MacBook screens

Lid-closing damage is extremely common — a pen, an earbud, or even a stray crumb left on the keyboard can crack the panel from pressure alone when the lid closes, often without anything that felt like a real “drop.”
Backpack compression is another frequent cause, particularly when a MacBook is packed alongside books, chargers, or other rigid items.
“Flexgate” is a well-documented issue specific to certain 2016–2017 MacBook Pro models, where a thin display flex cable wears out from repeated opening and closing, causing a “stage light” effect of uneven brightness along the bottom of the screen, eventually progressing to backlight failure. Apple ran a free Display Backlight Service Program for some of these models, but the eligibility window for that programme has now closed for virtually all affected units given their age — if you’re seeing this symptom on a Mac this old today, expect a paid repair.
The display is a single fused assembly on modern MacBooks, not separate glass over a panel. This means “screen repair” almost always means replacing the entire lid/display assembly rather than just a pane of glass, which is the main reason MacBook screen repairs cost more than people initially expect.

iMac screens

Cracking from everyday use is rare. An iMac’s display doesn’t get carried around or folded, so the cracks common on MacBooks essentially don’t happen here — damage is almost always from an impact during moving, transport, or an accidental knock.
The more common iMac display issue is gradual ageing, not cracking — panel or backlight degradation, or a yellowing tint that can develop on some older panels over many years of use.
On Retina iMacs, the logic board is mounted to the back of the display assembly, which means “screen replacement” can involve far more of the machine than people expect, and is worth understanding before requesting a quote.

Is it worth fixing?

As with any ageing device, screen repair cost is worth weighing against the Mac’s age, remaining macOS update eligibility, and realistic resale value — a straightforward conversation our Mac repair team can usually have with you before any work begins, rather than after.

Mac-Specific Security Myths and Scareware

The “Macs don’t get viruses” myth is genuinely worth retiring — Macs can and do encounter malware, and the bigger real-world risk for most Mac users isn’t a virus in the traditional sense but scareware: fake pop-ups claiming your Mac is infected and urging you to download a “cleaner” app, or fake prompts to update Flash Player (a piece of software that hasn’t even been supported for years). These rely on convincing you to install something yourself rather than exploiting a technical flaw, which is precisely the kind of social-engineering pattern covered in more depth in our Cybersecurity & Data Protection Guide. The safest response to any unexpected “your Mac is infected, click here” pop-up is simply to close it without clicking anything inside it.

Buying or Selling a Secondhand Mac in NZ

Secondhand Macs move briskly through Trade Me and Facebook Marketplace in Auckland, and there’s one check that matters more than any other before handing over money: Activation Lock.

Check Activation Lock status before buying. With the Mac powered on, go to the Apple menu, choose About This Mac, then System Report, and look under Hardware for “Activation Lock Status.” It should say Disabled. If it says Enabled, or the Mac shows a screen asking for someone else’s Apple Account to reactivate it, walk away unless the seller can remove it from their own account in front of you — Apple can generally only assist with this using the original proof of purchase.
Look up the serial number at checkcoverage.apple.com to confirm the model, manufacture details, and remaining warranty or AppleCare coverage before you buy.
After a legitimate purchase, reinstall macOS via Recovery Mode (restart and hold Command-R) for peace of mind — this clears out any leftover accounts or settings and gives you a clean copy of macOS directly from Apple.
If you’re selling, make sure Find My is fully turned off and the Mac is erased before handing it over, so the new owner doesn’t run into Activation Lock themselves.

Auckland-Specific Considerations

Humidity and dust accumulate faster here than in drier cities (Auckland’s average relative humidity sits around 82%), which makes cooling and cleaning more relevant locally than they might be elsewhere — see our Computer Cleaning Guide for the full explanation.
A large student and young-professional population across Auckland relies heavily on MacBooks for study and work, which means screen damage and battery wear tend to cluster around exam periods and the start of new study or work years, when devices get used more intensively than usual.
The secondhand Mac market here is large and largely unregulated beyond Trade Me and Marketplace’s own policies, which makes the Activation Lock check a genuinely common, practical issue for Auckland buyers rather than a theoretical one.

Frequently Asked Questions

Why is my Mac running slow? Most slowdowns come from background processes, a nearly full drive, Spotlight re-indexing after an update, or running an outdated version of macOS. Genuinely old hardware running the newest macOS version can also feel slower simply because each new release expects more from the hardware than the last.

Can I upgrade the RAM in my MacBook or iMac? Usually not on a MacBook — RAM has been soldered to the logic board on virtually all models since around 2012. Some older iMacs, roughly 2012 to 2019 depending on model, have a user-accessible RAM door, which is one of the few genuine upgrade paths available on an ageing Mac.

How do I know if my Mac’s battery needs replacing? Check Battery Health in System Settings for cycle count and overall condition. A battery that’s visibly swollen, causing the case or trackpad to lift, should be treated as a safety issue and assessed professionally as soon as possible, not just a performance concern.

Is it true Macs don’t get viruses? No. Macs can and do encounter malware, though the more common real-world risk is scareware — fake “your Mac is infected” pop-ups designed to get you to install something harmful yourself, rather than a technical exploit.

What is Flexgate, and does my MacBook have it? Flexgate is a documented display fault affecting some 2016–2017 MacBook Pro models, caused by a flex cable that wears out from repeated lid opening and closing, producing an uneven “stage light” effect at the bottom of the screen. Apple’s free repair programme for eligible units has now closed given how old these machines are, so a Mac showing this symptom today would need a paid repair.

How do I check if a secondhand Mac is locked before buying? With the Mac powered on, check About This Mac > System Report > Hardware > Activation Lock Status. It should say Disabled. If it’s Enabled or asks for someone else’s Apple Account, don’t buy it unless the seller removes the lock from their account in front of you.

How long does Apple support a Mac with macOS updates? Typically around seven to eight years of major macOS version updates from release, varying by model, with smaller security patches sometimes continuing a little beyond that. Apple’s coverage lookup tool can confirm a specific Mac’s status using its serial number.

About This Guide

Advanced Computers has been diagnosing and repairing Mac hardware since 1998, serving the CBD, East Auckland, Penrose, and North Shore, with day-to-day experience across both MacBook and iMac repairs, from screen and battery work to slow-Mac diagnostics.

This guide reflects our own iMac and MacBook repair experience together with publicly available Apple guidance, and is intended for general information. If your Mac is showing signs of battery swelling, persistent overheating, or a security compromise, a professional assessment is the safest next step.

Sources

Apple Support — Activation Lock for Mac
MacRumors — ‘Flexgate’ Display Issues Affecting 2016 MacBook Pro and Later

The Complete Mac Maintenance Guide to MacBooks and iMacs