2020 MacBook Pro chimes repeatedly when closed

If it only chimes when the lid is closed and the battery hits 100%, that usually means the machine is momentarily waking up, seeing the charger reconnect, and playing the “fully charged” sound on loop.

On Intel MacBook this is almost always one of three things, a flaky USB-C power cable, the charger briefly dropping voltage, or the battery controller waking the system because of a calibration glitch. Since it’s a refurb, it’s worth trying a different USB-C cable and a different charger first, that alone fixes this issue more often than not.

Also check System Settings → Battery → Options and disable “Wake for network access,” which can reduce random lid-closed wakeups. If the loop continues only at 100%, the battery’s charging board may be aging or out of spec, and at that point it’s best to return it or let Apple run diagnostics to confirm a hardware cause

mikeoa wrote:

Thanks for the help everybody. I did a deep dive down the rabbit hole and figured out the issue. It is the Power Adapter that is causing the issue. The one that they sent is a 87W and per Apple the unit would have came with a 61W, not sure if the extra wattage is the problem or if this unit is just defective. But one of the things that gave it away is when I would shutdown the unit on battery power it would shut down as expected but if it was plugged in it would restart like I hit the restart and not shutdown. I tried a 60W power adapter from another non apple computer and all of the gremlins went away. I contacted the Amazon seller and they are sending the correct Power Adapter. Thanks Again

Good computing mikeoa ! — appreciate the report.

Power Adapter would be considered hardware.

mikeoa wrote:

2020 MacBook Pro, Intel I5 Processor, doing the Battery 100% Charged Chime repeatedly when the clamshell is closed.

It does not do it any other time.

It has an Apple 87W power adapter and I have done a SMC Reboot as well as ran Apple Diagnostics and it came back with no errors.

You do not say what macOS...?

old issue, new issue, what changed?

—could be due to a MagSafe charger issue, unplug the charger from the power source and remove all cables for 60 + secs. then plug it all back in to compare your results. This will reset the internals.

—a power chime hardware problem

— issues with the firmware— firmware updates happen during macOS Updates and upgrades, verify your macOS is up to date.

—try a USBC charging cord direct to the mac(?)

—try a different wall socket opposite end of the house...

mikeoa wrote:

Thanks for all of the questions.

OS - Tahoe 26.1

This is a new to me unit. Purchased a refurbished unit from Amazon.

The only cable that is hooked up is the charger, and the only time it does this is when the unit is fully charged to 100% and the lid is closed. Right now the unit is at 65% and the lid is closed and there is no problem.

Ok— if no resolve with the list of suggestion above take it in.

I would not rule out a hardware issue.

In or out of warranty you can get a free over the counter 'Apple Service Diagnostics' test /assessment

Make an appointment for a "hardware issue"

Genius Bar Reservation and Apple Support Options - Apple

Outside the USA

Contact Apple Support - Apple Support

Check Device Coverage View Coverage - AppleCare & Warranty

Get your Mac ready for service - Apple Support   Get your Mac ready for service - Apple Support

Alternatively— return for a refund or exchange (if available through your Amazon‚) for one that works as expected out of the box.

That is normal. Because apple got rid of the little battery status that used to be on the side of macs I guess this is the replacement.