Technical support request for Apple Studio Display M 7613

Crizzi71

New Tinkerer
Oct 8, 2025
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0
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Hello Guys Thank you for accepting me into your group and I hope someone can help me...


I am reaching out to ask for your support with an Apple Studio Display model M7613 (late 1990s), which I have not been able to power on. Below I describe the situation in detail:


  1. Monitor and missing original power supply
    • This monitor requires an external power adapter rated 24V DC, 1.875A, center positive (Apple part number M4551).
    • Unfortunately, the original adapter is difficult and expensive to find.
  2. Alternative power supply purchased
    • I bought a universal adjustable power supply, model LGY-002, with the following specifications:
      • Input: 100–240V AC, 50/60 Hz
      • Output: adjustable DC 3–24V, max 3A
      • Standard polarity: center positive (with interchangeable barrel plug adapters).
      • I set the voltage to 24V.
  3. Connection
    • The monitor has a built-in cable with a barrel DC connector.
    • To connect it to the power supply, I used one of the universal adapter tips, but I am not sure the fit is solid.
    • Also, since I don’t have a multimeter, I could not verify the polarity.
  4. Tests performed
    • I connected the monitor to power only (without a computer) to check if at least the power LED would turn on.
    • Unfortunately, the monitor shows no LED activity or signs of life.
    • I am wondering whether the monitor should power up on its own, or only when connected to a computer with a video signal.
  5. Main doubts
    • The issue might be caused by reversed polarity or a poor contact in the connector.
    • I am unsure if this universal adapter is safe and adequate, or if the Apple original one is strictly required.
    • I don’t know if the monitor should at least show a standby LED when powered without a computer.


  • confirm whether the universal power supply I am using is suitable and safe,
  • advise on the correct way to power this monitor,
  • provide practical instructions for testing it (possibly by connecting it to a compatible computer).


Thank you very much

Best regards,

Cristiano Rizzi