iMac 24" M1 that won't turn on: the external power brick, and the rest
An iMac as thin as a tablet, with a power brick on the floor. When it won't turn on, that is often where it happens, but not always.
The 24" iMac (M1, then M3 and M4) moved its power supply into an external unit, linked by a cable with a magnetic connector. That simplifies many diagnoses, and complicates a few.
The external power supply
A thunderstorm, a tired power strip, or simply age: the brick no longer delivers its voltage, or cuts out under load. We test it in the workshop; if it is at fault we replace or repair it. First check that the magnetic connector is clean and fully seated: a hair is enough to break the contact.
The logic board
If the power supply is fine, we open the iMac (the screen is bonded and must be lifted cleanly) and look on the board: power circuit, short, or a failed chip. Component-level repair, fixed price on the prices page.
The other faults
- The Mac boots but the screen stays black: backlight or flex.
- It shuts down under heavy load: clogged fans, thermal paste to redo.
- Soldered storage: as on a MacBook, data recovery goes through the logic board (249 €).
Bring the power brick and its cable with the iMac: without them the diagnosis is incomplete. An iMac travels well by carrier in its original box; otherwise book an appointment in Miélan.
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