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iMac Repair in London — Screens, SSD Upgrades and No Power

All-in-one repairs done properly — including the SSD upgrade that rescues a slow iMac

Call 020 7610 0500 WhatsApp Us Get a Free Quote
4.8-star Google rating 25+ years experience Free collection & return 90-day warranty on repairs

Last updated: August 2026

Overview

The upgrade that rescues most slow iMacs

Most iMacs that reach us are not broken — they are crawling. Any iMac still booting from a spinning hard drive or a Fusion Drive spends its day waiting on that disk, and no amount of tidying up macOS will change it. Replacing it with an SSD is the single biggest difference you can make to one, and it routinely turns a machine somebody was about to replace back into a fast desktop. We handle the genuinely broken side as well: display faults, machines that show no power or no picture, fan noise, overheating and memory. An iMac is heavy and awkward to move, so you can either walk it in to our Putney shop or we will collect it and bring it back, free, across South West London.

Screen and display repairs, including backlight and image faults
Hard drive or Fusion Drive replaced with an SSD, with everything migrated across
No-power and no-picture diagnosis, from power supply to logic board
Fan noise, dust and thermal faults on Intel iMacs
Memory upgrades on the models that allow one — and a straight answer on the ones that do not
SSD upgrades that transform older iMacs Free collection and return Honest on what is worth doing
Why an SSD is the single biggest iMac upgrade Display faults: what is the panel and what is not No power, no picture and fans at full speed
What you get

What every imac repair job includes

90-day warranty

The work we carry out is covered by a 90-day warranty. If the same fault comes back inside that window, we put it right.

Free collection and return

We collect and return across South West London at no charge, so you do not have to make the trip to get your machine looked at.

Same-day turnaround is available on many jobs — ask when you book and we will confirm availability and any additional cost before we start.

Features

What Our iMac Repair Service Covers

SSD Upgrades

The fix for a slow iMac. We replace the hard drive or Fusion Drive with an SSD and migrate macOS, your applications and your files across, so you sit down to the same desktop — just fast.

Screen & Display Repairs

Cracked glass, failed backlights, vertical lines, image distortion and dust behind the panel. On the slim iMacs the display is bonded to the chassis with adhesive, so it comes off and goes back on with fresh adhesive strips — not tape.

No-Power Diagnosis

An iMac that will not start is usually the internal power supply, the power button assembly or the logic board. Intel iMacs carry four diagnostic LEDs on the board that show how far through the start-up sequence the machine gets before it stops.

Fan Noise & Overheating

Constant fan noise on an iMac is rarely just dust. A failing drive, a blocked vent path, dried-out thermal compound or a hard-drive temperature sensor left unresolved after an earlier upgrade will each do it, and each needs a different fix.

Memory Upgrades

27-inch iMacs have a memory hatch behind the stand and take minutes. Most 21.5-inch models need the display off first, and on several the memory is soldered and cannot be changed at all. We confirm which yours is before anything is ordered.

Collection and Return

An iMac is a two-handed, awkward thing to carry across London. We collect and return free across South West London, pack it properly for the journey, and the machine is fully insured while it is with us.

Process

How an iMac Repair Works

Simple steps to get your problem solved quickly and professionally.

1

Tell us the symptoms

Call 020 7610 0500 and describe what the iMac does — no chime, no picture, painfully slow, roaring fans. The model year changes the answer considerably, so the serial number from the foot of the stand helps.

2

Walk in or we collect

Bring it to 66 Lower Richmond Road, Putney, SW15 1LL, or we collect free from anywhere in South West London and return it the same way once it is done.

3

Diagnosis, then a clear price

We test the machine properly and come back with the fault, the cost and an honest view on whether it is worth spending. Nothing is ordered until you have agreed the quote.

4

Repair, test and return

We carry out the work, then run the iMac warm and under load to prove it is stable rather than merely switched on. The work is covered by a 90-day warranty.

In Depth

What to Expect

Prefer the quick version? The sections above cover most needs. Expand any topic below for more detail.

Why an SSD is the single biggest iMac upgrade

More iMacs come to us slow than come to us broken. Almost every one of them has the same thing in common — a mechanical drive doing work an SSD should be doing.

The drive is the bottleneck, not the processor

An iMac from 2013 to 2019 has a processor that is still perfectly capable of everyday work. What it does not have is a drive that can keep up with a modern macOS, which is why the beachball appears while the machine sits doing nothing visible.

Fusion Drives age badly

A Fusion Drive pairs a small SSD with a large hard disk and presents them as one volume. It works well when new and progressively less well as it fills, because the fast half runs out of room and the slow half takes over. Splitting it and moving to a single SSD ends that.

Your setup comes with you

We clone the existing installation rather than starting fresh, so macOS, your applications, your accounts and your files arrive on the new drive exactly as they were. Where a drive is already failing, we recover first and migrate second.

The thermal sensor gets handled properly

Older iMacs take the internal drive's temperature from a sensor tied to the original Apple drive. Ignore that during an upgrade and the fans howl permanently afterwards. It is the commonest complaint we hear about upgrades done elsewhere, and it is dealt with as part of the job here.

For most iMacs of that era this is a one-afternoon change that buys several more years of use for a fraction of the cost of replacing the machine.

Display faults: what is the panel and what is not

An iMac panel is the single most expensive part in the machine, so it is worth being sure it is the panel before anybody quotes for one. What we check:

  • Cracked or shattered glass on a Retina iMac — glass and LCD are bonded, so this genuinely is a display assembly
  • Backlight dead but a faint image still visible under a torch — a backlight circuit fault, often repairable on the board
  • Vertical or horizontal lines, blocks of colour, or a distorted image — frequently the graphics side rather than the panel itself
  • Dust, smears or marks behind the glass on 2009–2011 iMacs — the glass lifts off magnetically on these, so it is a clean
  • Image fine on an external monitor but not on the built-in screen — narrows the fault to the display path
  • Intermittent flicker or dimming that follows a knock or a move — usually a cable or connector rather than the panel

On 2012 and later iMacs the display is bonded to the chassis with adhesive strips. Opening one is a controlled process, and it goes back together with fresh adhesive so the seal and the alignment are as they should be.

No power, no picture and fans at full speed

These three symptoms account for most of the genuinely faulty iMacs we see. They are separate problems with separate causes:

  • Completely dead, no fan, no chime — the internal power supply is the first thing to test, followed by the power button assembly
  • Fans spin, no chime, no picture — the board is receiving power but not completing start-up; the diagnostic LEDs narrow this down quickly
  • Chime and Apple logo, then a stall or a question-mark folder — a storage or macOS problem rather than a hardware failure
  • Fans at full speed from the moment it starts — a missing or misread temperature sensor, very often after a previous drive change
  • Fans ramping up under light load, machine hot to the touch — dust in the vent path and thermal compound past its life
  • Random shutdowns when the room is warm — thermal protection doing its job, which points at cooling rather than the board

Because an iMac hides everything behind a bonded display, guesswork gets expensive. We diagnose first and quote from the answer, not from the symptom.

Getting a heavy all-in-one repaired

The practical side of iMac repair, which nobody mentions until you are trying to fit a 27-inch machine into a car:

  • Walk in to 66 Lower Richmond Road, Putney, SW15 1LL — Monday to Friday 10:00–18:00, Saturday 10:00–17:00, closed Sunday
  • Or book free collection and return across South West London and we will do the carrying
  • Bring the power cable; the keyboard, mouse and any external drives can stay at home unless the fault involves them
  • Back up first if the machine still runs — and tell us if it does not, so we treat the drive accordingly
  • The machine is fully insured from the moment we collect it until it is back with you
  • Same-day turnaround is available on some jobs; the surcharge for it is confirmed when we quote

One honest note: on a very old iMac with more than one significant fault — say a failed panel and a board problem together — the sums stop working. We will tell you when that is the case rather than take the job.

Not sure what you need? We're happy to help.

Call us or Get a free quote
Pricing

iMac Repair Pricing

Every iMac is quoted for its own model and fault. A 2015 27-inch with a dying hard drive and a 2019 21.5-inch with a display fault are not the same job, and a single headline price would only be wrong for one of them. You get a clear figure after diagnosis and before any parts are ordered. Same-day turnaround is available on some jobs, with the surcharge confirmed when we quote.

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90-Day Warranty · Clear Quote Before Any Work

FAQ

Frequently Asked Questions

Is it worth upgrading an older iMac to an SSD?
In most cases it is the best money you can spend on one. An iMac still booting from a spinning hard drive or a Fusion Drive is held back by that drive rather than by its processor, and a 2015 or 2017 machine with an SSD fitted feels quicker day-to-day than it did new — boot, waking, opening applications and Photos libraries all stop waiting on the disk. We clone macOS, your applications and your files onto the new drive, so nothing has to be set up again. Our SSD upgrade service explains how the migration works.
My iMac will not turn on at all — what is usually wrong?
On an iMac there are three usual suspects: the internal power supply, the power button and its cable, or the logic board. Intel iMacs have four diagnostic LEDs on the board showing how far the start-up sequence gets, and where it stops tells us a great deal — LED 1 lit with LED 2 dark points somewhere quite different from all four lit with no picture on screen. Where the fault turns out to be on the board itself, that is logic board repair at component level rather than a board swap, which is usually far cheaper.
My iMac's fans run flat out since a drive was replaced. Why?
That is a classic and it is fixable. Older iMacs read the internal drive’s temperature through a sensor built into the original Apple drive or its cable. Fit a standard replacement without dealing with that sensor and macOS gets no temperature reading, assumes the worst and runs the fans at full speed permanently. It is not a fault in the new drive and it is not something you have to live with — it is the sensor circuit, and it is resolved either with the correct sensor arrangement or by restoring the reading the machine expects.
Can an iMac screen be repaired, or does the whole display get replaced?
It depends what has actually failed, which is why we diagnose before quoting a panel — the panel is the expensive part. Cracked glass on a Retina iMac does mean the display assembly, because the glass and the LCD are bonded together and cannot be separated. But plenty of faults that look like a broken screen are not the panel at all: a dead backlight, vertical lines or image distortion can come from the backlight circuit or the graphics side of the board, and dust or marks behind the glass on pre-2012 iMacs are a clean rather than a replacement.
Can I add memory to my iMac?
On 27-inch iMacs from 2012 to 2020, yes — there is a hatch behind the stand and it is a quick job. On most 21.5-inch models the memory sits behind a glued display, and on several of them it is soldered to the board and cannot be changed at all. On the 24-inch M-series iMacs the memory is part of the chip, so it is fixed at whatever specification was bought. Tell us the model year and you will get a yes or a no rather than a maybe.
My iMac's drive has failed and I have no backup. Can the files be saved?
Often, yes, and on an iMac it is worth attempting first, because the drive has to come out for an SSD upgrade anyway. Fusion Drive machines need care: they present a small SSD and a hard disk as one volume, so any recovery has to account for both halves rather than treating it as a single drive. Our data recovery service covers how the assessment works and what is realistic.
How do I get a heavy iMac to you?
Two ways. Walk it in to 66 Lower Richmond Road, Putney, SW15 1LL — we are open Monday to Friday 10:00–18:00 and Saturday 10:00–17:00, closed Sundays. Or we collect and return free across South West London, which is what most iMac customers choose. Either way the machine is fully insured while it is with us. Call 020 7610 0500 if you are not sure which is easier.
Do you repair Apple silicon iMacs?
Yes, including the 24-inch M-series models. What changes is what is possible on them: the memory is part of the chip and the storage is soldered to the board, so neither can be upgraded after purchase. Displays, power faults, ports, stands and board-level work are all still repairable. We would rather say that plainly than have somebody carry one in expecting an SSD upgrade that does not exist on that model.
Do you repair MacBooks and other Macs too?
Yes. Laptops are a different discipline — different disassembly, different failure patterns, different parts — so they have their own page: MacBook and Mac repair. Between the two we cover the range, and if you are weighing up whether repairing the iMac or moving to a laptop makes more sense once you have the quote, we are happy to give you a straight view.

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Service Areas

We provide iMac Repair in London — Screens, SSD Upgrades and No Power across South West London

Serving Wandsworth, Wimbledon, Putney, Clapham, Balham, Tooting, and surrounding areas.

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iMac Slow, Dead or Deafening?

Tell us the model year and what it is doing, and we will tell you what is likely, what it costs and whether it is worth the money. Walk in to Putney, or we will collect it free across South West London.

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