iMac 27'' Intel (2012–2020) – known issues, upgrades and repair
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Quick answer
The iMac 27'' Intel (2012–2020) is one of Apple's most durable desktops. The main faults are Fusion Drive failures (the HDD part starts clicking), power supply wear after 5–7 years, and GPU thermal throttling on later models. Screen and RAM upgrades are possible on most 27'' models. We repair every iMac 27'' Intel.
About the iMac 27” Intel (2012–2020)
Apple’s best-selling desktop for nearly a decade. 5K Retina display from 2014, expandable RAM, Fusion Drive or pure SSD as an option. Replaced by the iMac 24” M1 in 2021 (but the 24” has a smaller screen — there’s no direct 27” successor from Apple).
Specifications (2020 model):
Chip: Intel Core i5/i7/i9 (10th generation)
RAM: 8–128 GB DDR4 (upgradable)
SSD: 256 GB – 8 TB
Display: 27” 5K Retina (5120×2880)
Known issues by generation
2012–2015: Fusion Drive HDD failure is typical after 7–10 years. A pure SSD upgrade is recommended.
2017: “Soft” GPUs — the Radeon Pro 580 runs hot and loses performance over time (needs cleaning + thermal paste replacement).
2019–2020: the last Intel iMac. Solid. The main issue is still Fusion Drive (where applicable) and PSU wear after many years.
A 2017+ iMac 27” Intel with a pure SSD and 32 GB RAM is still an excellent everyday computer in 2026. If yours is running Sonoma or Sequoia, repair it and keep it going. The new iMac M4 starts at DKK 12,000 — often an old iMac can be repaired for significantly less and last another 3–5 years.
Frequently asked questions
My iMac 27'' Intel is clicking — what should I do?▾
It's the HDD part of the Fusion Drive that's dying. STOP using the iMac and back it up quickly (or bring it to us first). We can replace the HDD with a pure SSD as a permanent fix, which also dramatically improves performance. Price: DKK 2,500–4,000 including the SSD.
Can I upgrade RAM on the iMac 27'' Intel?▾
Yes, on most 27'' models (2012–2020) — there's a RAM access door behind the screen. Up to 64 GB on most models, 128 GB on the 2020 model. It gives a noticeable boost on older models with 8 GB.
What does a screen replacement cost on the iMac 27''?▾
DKK 3,500–5,500 depending on generation. iMac displays are glued in, so the repair takes precision — but we have the specialist equipment. See current pricing at macmo.dk/reparation.
My iMac 27'' won't turn on — what's it usually?▾
In 60% of cases: a faulty power supply (PSU). In 25%: a faulty power button or its flex cable. In 15%: the logic board. We diagnose in 30–60 minutes.
Should I upgrade my Fusion Drive to a pure SSD?▾
Absolutely. It's the single most valuable upgrade on an older iMac. The SSD makes the iMac 5–10x faster, eliminates the Fusion Drive's classic fault patterns, and typically gives 5+ extra years of life. We do it for DKK 2,500–4,000 including a quality SSD.
