iMac 21.5 & 27-inch Unibody (2009–2011) Power Supply Repair

Apple iMac

If your iMac Unibody (2009–2011) needs power supply repair, our London technicians can help, usually with a quote on the same day you bring it in.

The power supply in the 27-inch A1312 is a common failure. Symptoms are no power, clicking or shutdowns. We test it under load and replace or repair it, then check the logic board for knock-on damage.

About this model: The 2009–2011 unibody iMacs (A1311 21.5-inch and A1312 27-inch) have the magnetically held glass, which makes getting inside easier than later glued models. They have four RAM slots behind a door and a 3.5-inch hard drive.

Signs it needs power supply repair

  • No power
  • Shuts down randomly
  • Clicking noise
  • Burning smell

How we do it

We test the power supply under real load (a multimeter check without load can pass a failing unit), then replace or repair it at component level where a new unit isn’t available.

Because a failing supply can damage other parts on its way out, we also test the logic board and drive afterwards.

At a glance

Years 2009–2011
Processor Intel Core 2 Duo, then Core i3/i5/i7
Storage Standard SATA drive
Memory Socketed, upgradeable
Power / charging Internal mains power supply

Before you bring it in

Tell us whether it does nothing at all, clicks, or starts and cuts out, and whether there was a recent power cut or surge.

Which model do you have?

This page covers the iMac 21.5 & 27-inch Unibody (2009–2011) (iMac10,1 / 11,x / 12,x; A1311, A1312). About This Mac in the Apple menu shows the model and year; the A-number is printed on the underside of the stand. Not sure? Bring it in and we’ll identify it for you.

Price

We give you a fixed quote after a free initial assessment, before any work starts. The initial assessment and advice are free, as long as we don't need to open your Mac. If a technician needs to open it and spend time diagnosing the fault, or you need a report for an insurance claim, it is booked in as a diagnostic at £45 + VAT (£54). All prices are subject to inspection, and nothing is done without your approval.

Questions we’re often asked

Is a Mac this age worth repairing?

It depends what you use it for. For recovering data, running legacy software or keeping a working studio setup, often yes. We give you the cost upfront and an honest view on whether it makes sense.

Is there a warranty?

Yes, our repairs come with a warranty on the work and parts. Ask us for the terms that apply to your repair.

Book a repair

For a free, no-obligation quote, call 020 7394 2528 or email info@mac-repair.london.