iMac 27-inch 5K 2015-2017 Repair Johannesburg | iAssist
iMac 27-inch 5K Repair2015 & 2017 Intel models
The 5K iMac everyone misses — and the one iStore now turns away. Premiere crashing with artefacts? Kernel panic on a 4K timeline? Boot taking five minutes? Classic late-Skylake/Kaby Lake problems. We re-ball the GPU, swap the Fusion Drive for SSD, OCLP the macOS forward. Free diagnostic.
Free diagnostic · RAM via rear panel · AMD GPU restoration · 6-month warranty
iMac 27-inch 5K (2015–2017) at a glance
Display
Retina 5K 27-inch · 5120×2880 · P3 wide colour (2017)
Models
iMac17,1 (Late 2015) · iMac18,3 (Mid 2017)
Processor
Intel Core i5 / i7 3.2–4.2GHz (Skylake/Kaby Lake)
RAM
Up to 64GB DDR4 2400MHz (2017) / 64GB DDR3 1867MHz (2015) · rear panel
Storage
PCIe NVMe blade + optional SATA HDD · Fusion Drive on some configs
GPU
AMD Radeon R9 380/395 (2015) · AMD Radeon Pro 570/575/580 (2017)
Ports
4× USB-A · 2× Thunderbolt 2/3 · SD card · Ethernet
Known issue
AMD Radeon GPU solder failure — common on both years as machines age
What we repair on the iMac 27-inch 2015–2017
The link between heat and AMD GPU failure on the 2015–2017 27-inch
The AMD Radeon GPU failures that affect 2015 and 2017 27-inch iMacs are not random — they are accelerated by heat. As thermal paste dries out over years of use, CPU and GPU temperatures climb. The GPU solder joints — already stressed by the normal thermal expansion and contraction of daily use — fail faster under elevated temperatures. A thermal service does not guarantee the GPU will never fail, but it significantly extends the window before it does.
| Thermal service stage | What we do | Why it matters |
|---|---|---|
| Display removal | Professional separation, OEM adhesive removed cleanly | Safe access without panel damage |
| CPU thermal paste | Old compound removed, fresh Noctua NT-H1 applied | CPU temps drop 10–20°C under load |
| GPU thermal paste | AMD Radeon die cleaned and recompounded | GPU temps drop 15–25°C — direct impact on solder longevity |
| VRAM thermal pads | Factory pads replaced with fresh pads | VRAM runs cooler — often overlooked by other shops |
| Full internal dust clean | Heatsink fins, fans, vents — all cleared | Airflow restored to factory levels |
| Display reseal | OEM VHB adhesive strips fitted, display pressed | Factory-quality seal |
iMac 27-inch 5K (2015–2017) repair price guide
Estimates only. Final price confirmed after free diagnostic. Written quote before work begins.
| Service | Estimate |
|---|---|
| Screens & display | |
| 5K display assembly replacement Laminated 5K panel. LG panel failure common on Late 2015 models. |
R5,500 – R8,500 |
| Backlight / TCON repair Flashlight effect, backlight failure, or display lines. Panel may be reusable. |
R1,500 – R3,000 |
| Logic board & GPU | |
| AMD Radeon GPU restoration logic board replacement. Most common fault on both model years. |
R2,000 – R3,500 |
| Logic board — component-level repair Power rail, USB/TB controller, SMC fault. Component-level microsoldering. |
R1,500 – R5,500 |
| Power supply replacement (300W, A1419) PSU unit R2,999 + display removal labour + OEM adhesive strips. |
R4,500 – R5,000 |
| Storage & memory | |
| RAM upgrade — per 8GB 2017: DDR4 2400MHz. 2015: DDR3 1867MHz. Rear panel — no display removal. |
R1,600 / 8GB |
| SSD upgrade (NVMe blade) PCIe blade upgrade without display removal on 27-inch. |
Quote on request |
| Fusion Drive → pure SSD conversion Remove Fusion pairing. Single SSD boot drive for full performance. |
Quote on request |
| Thermal & other | |
| Thermal paste + full dust clean CPU/GPU thermal compound + internal dust clean. Display removal. |
R650 – R1,600 |
| Liquid damage treatment Ultrasonic clean, corrosion removal, component repair. |
R900 – R2,800 |
| Data recovery Drive removed directly — no T2 chip on these models. |
R900 – R2,800 |
| macOS upgrade via OpenCore Sonoma via OCLP on 2015 and 2017 models. SSD + 8GB RAM required. |
R1,500 |
| Collection and return — Gauteng Door-to-door via Eliz Courier. |
R500 |
Which iMac do you have?
Jump to your exact model for model-specific pricing, parts, and known faults.
iMac 24-inch M-series
View M-series repairs → 2017 XeoniMac Pro
View Pro repairs → 2019 - 2020iMac 27-inch (late Intel)
View 27" late Intel repairs → 2015 - 2017iMac 27-inch 5K
View 27" 5K repairs → 2013 - 2014iMac 27-inch
View 27" early repairs → 2017 - 2019iMac 21.5-inch 4K
View 21.5" 4K repairs → 2013 - 2015iMac 21.5-inch
View 21.5" early repairs →Free diagnostic
We confirm the exact fault before quoting — no charge if we can't help or the repair doesn't make financial sense.
Component-level repair
Microsoldering means we fix what others write off. We replace the failed chip, not the whole board.
Written quote first
Fixed price confirmed in writing before any work begins. No surprises on collection.
6-month warranty
All parts and labour carry a 6-month warranty. If the same fault reoccurs, we fix it.
Data stays safe
We never start a repair that could affect your data without securing it or getting your explicit approval first.
R500 Gauteng collection
Insured door-to-door collection and return anywhere in Gauteng. iMacs are heavy — we handle transport.
Three ways to get your iMac to us
Drop it off, arrange Gauteng collection, or ship from anywhere in South Africa. iMacs are heavy and the displays are fragile — we transport them properly.
Drop it off at the workshop
Walk in to our Silvamonte workshop any business day. Free parking, free diagnostic on the spot. Bring the original box if you still have it — otherwise we have appropriate transport packaging on hand.
11 Swemmer Rd, Silvamonte, Johannesburg
Mon-Fri 08:00-17:30 · Sat 08:00-14:00
Door-to-door via Eliz Courier
Eliz Courier & Messenger Services collects and returns your iMac across Joburg, Pretoria, Centurion, and the East Rand. R500 round-trip — slightly higher than our laptop rate because iMacs need specialist transport packaging and careful handling.
WhatsApp to book collection →Ship via The Courier Guy
Anywhere in South Africa — Cape Town, Durban, PE, Bloem, Polokwane. We arrange Courier Guy collection from your door with proper iMac packaging, repair, and return. Pricing depends on size; WhatsApp us with your model.
WhatsApp to arrange courier →iMac 27-inch 5K 2015–2017 — FAQ
My 2015 or 2017 iMac 27-inch shows screen artefacts and distortion — what is wrong?
This is almost certainly AMD Radeon GPU solder failure — the most common fault on both model years. The GPU die develops micro-fractures in its BGA solder joints under years of thermal cycling. iAssist restores the GPU at chip level through board replacementing and board replacement — in most cases this fully resolves the fault.
How much RAM can my 2017 27-inch iMac support?
Apple officially supports 64GB DDR4 2400MHz. In practice, all 2017 27-inch models support up to 64GB via four SO-DIMM slots in the rear panel — no display removal needed. RAM is R1,600 per 8GB module.
Is the 2015 27-inch iMac still worth repairing?
Yes — these are excellent machines with Retina 5K displays that are otherwise in good condition. GPU restoration costs significantly less than replacement and gives years more life. With an SSD upgrade and fresh thermal paste these machines perform very well.
Can you upgrade the SSD on my 2015 or 2017 27-inch?
Yes. The PCIe NVMe blade slot on the 27-inch is accessible from the rear without display removal. We can upgrade to a much faster, larger blade drive. Contact us for a quote.
Do you offer collection for the iMac 27-inch?
Yes — R500 insured door-to-door collection and return across Gauteng. WhatsApp us on 078 742 4769.
My 2015 or 2017 27-inch iMac screen has dust trapped inside — is that fixable?
Yes. The 2015 and 2017 27-inch iMac uses a laminated display assembly but dust can still accumulate at the edges between the display and the front glass. We clean the internal surfaces during any repair that requires display removal — and as a standalone service where the dust is significant enough to warrant it. Worth combining with a thermal service since the machine is already open.
Why does my 2017 iMac 27-inch fan spin up loudly just from using Chrome or watching YouTube?
Chrome and video playback are GPU-intensive tasks. On a 2015–2017 27-inch iMac with degraded thermal paste, GPU temperature rises faster than it should under moderate load — the fan responds aggressively. A full thermal service brings GPU temperatures down 15–25°C. After the service the fan stays quiet through normal use and only spins up under genuinely heavy sustained load.
My 2015 27-inch iMac shows display artefacts only when warm — not from cold. Is that still the GPU?
Yes, and this is the most diagnostic symptom of AMD GPU solder failure. The solder joint micro-fractures only open under thermal expansion — when cold the joints make contact and everything works. As the board heats up the fractures open and the GPU loses signal. This temperature-dependent pattern strongly indicates GPU solder failure. A thermal service may delay progression but board replacement is the definitive resolution.
