Mac Studio M2 won't boot - led flashes once

if they have replaced the main logic board, you are still using the same power supply board.

On the old Mac Pro, they way you discharged the power supply Voltage capacitors to get to Zero Volts inside was the remove the AC power cord, then press the power button for a few seconds. Doing that might get you ready for the next trial of your experiment more quickly.

There was in issue on older MacPro models that featured a power cord with a larger rubber block around the computer end of the power cord. Sometimes, users were 'too delicate' when inserting that end of the cord into the computer.

The solution was to JAM that end of the cord into the computer as hard as you reasonably could -- which produced much more stable and reliable results.

That solution might be applicable in this case as well.

Doubt this is an issue with plugs or power chord. Tried with new chord and didn't make a difference.

However, I noticed that after I plug the Mac Studio into new outlet, it doesn't boot up and flashes once, but if I wait about an hour it does power up. After shutting it down it restarts multiple times without any problem. If I unplug, replug in same outlet and try to restart it fails again. Same pattern on any plug, with or without PSU, with or without any external hardware connected (including monitor). Ran diagnosis and everything shows up as OK.

OK looks like many people took this to Apple for repair with the problem persisting. I'm inclined to think this might be a capacitor issue.

Same problem recently after I unplugged the MacStudio from wall, wouldn't start. Then I totally unplugged it from the back, pressed start button several seconds without unit being plugged at all. Replugged, & unit started fine. If other people experiencing same problem can try this?

If the SIL flashes white one or more times after you turn on the computer, there may be a hardware issue.

To isolate the issue, run Apple Diagnostics.

For that reference, go to the bottom of > Mac computer status indicator light behavior - Apple Support

Same problem here. Mac Studio M2, 1 year old.

If you are unplugging the Mac Studio or switching off the power to the wall outlet...?

Try shutting down the Mac Studio and leave it plugged into a live wall outlet.

The classic error in Intel Macs that was reported by single flash of the power indicator was firmware checksum error.

It is unclear what error is being reported by a single flash today, but a mainboard replacement should have fixed the original problem.

Yea, for some reason the "If you still need help, contact an Apple Authorized Service Provider" punch line, is up at the end of the "Firmware recovery mode" paragraph, instead of at the bottom of the article.

Perhaps the later "If the SIL flashes" paragraph was an add-on or after-thought....?

At home:

1) Are all of your power connections good and tight?

A week or loose connection could easily prevent the Mac from starting up properly.

2) Are you using external drives or devices with the Mac Studio?

A bad USB cable, device or display could easily prevent the Mac from starting up properly.

Could very well be a loose or not fully inserted power cord in the back of the Mac.

I've had a dozen or more panic calls from friends and family, saying that there Mac wouldn't turn on after dusting or turned it around to plug in a USB cable.

Experiencing exactly the same problem, same specs. Took it to repair, they detected a faulty mainboard and replaced it. Got it back last week and the issue still persists. Today I took it to repair again. Other posts on this issue don't exactly give me hope...