What causes MacBook Pro to restart while closed?

This is all a little premature.

You haven't provided enough information yet to decide this is an SSD problem. So far all symptoms you have reported are related to sleep/wake problems.

Consider downloading and running this little "discovery" utility, Etrecheck. It changes NOTHING. Etrecheck was developed by senior contributor here, and uses system calls to collect often-needed information.

it contains little tests for speeds of devices, CPU utilization, memory usage, energy usage and a digest of recent problems, in one easy to use package. it does not even need to be Installed. Because less can be learned when your Mac is running great, best time to run is when your problems are actually occurring, if possible.

if you follow the directions faithfully, its report (pre-laundered of all personally-identifiable information) can be "Shared" to the System ClipBoard, then Pasted into an ‘Additional Text’ window in a reply on the forums.

Use Etrecheck Pro for free:

http://Etrecheck.com

...Then start a reply, click additional text icon in the reply footer, and PASTE.

ChefJoseph wrote:

MacBook Pro 16" Late 2019. 8 core i9, 16 GB, 1TB. Starting with OS 15, I get this 1-2 times a week when the cover is closed. I hear the startup chime and this is what I see.

https://discussions.apple.com/content/attachment/575881c8-1544-4e77-bc39-47759c696477

Here are the details:

https://discussions.apple.com/content/attachment/2632d3d8-c4a5-4825-9ce3-266fde0a2576

https://discussions.apple.com/content/attachment/053c0869-adbd-4602-9265-cea3ef905e25

Any ideas?

Thanks,

Joseph

Are you still using the original internal SSD?

I ask because with certain internal SSD replacements (OWC provides some of these and has a technical article about it), because of a shift in timing between the SSD coming on and the rest of the Mac awaking, the SSD might not be available for a tiny fraction of a second when the Mac is looking for it and it panics. The solution (I have a replacement SSD on an older 2013 MacBook Air and this works) is suggested to be:

Open Terminal while logged in as an admin user and enter the following (password is required):

sudo pmset -a standby 0 

This will prevent a certain type of very deep sleep (but still allows normal sleep) and impacts battery usage very minorly. If this does not resolve this enter the same command with "1" instead of "0." It might be worth trying even if you have the original SSD, but in that case, if it works that might indicate that the SSD is aging and slowing done.

Next time it happens click the Report... button, copy the text and paste it here.

For what it's worth I have not seen the problem described in the link Grant Bennet-Alder provided (sleep / wake fault) that did not require replacing the logic board. Your problem may be different, so post your report.

Personally I don't consider the replies in that discussion very helpful. Disabling sleep mode is abnormal and should not be a considered an acceptable fix.

Needless to say, if you are using any non-Apple "anti-virus", "cleaning", or "Internet security" products including "banking security", anything at all in that broad category of utterly useless garbage, don't. A lot of things won't work if you do.

Use appropriate CAUTION when drawing broad conclusions about reliability.

scientists always rely on average performance from LARGE samples of items to draw conclusions that might be generally applicable.

you have a sample of ONE computer. ANYTHING could happen to your one unit, and not change overall reliability numbers in the slightest. Apple ships about 57,000 new computers a DAY.

Read If your Mac restarted because of a problem - Apple Support.

read this discussion, where similar issues are discussed at length:

Mac Desktop not waking from sleep - Apple Community

.

If you followed all those steps (all of them, including all the links) and the KP events persist, then contact Apple Support. The usual cause is defective hardware that only they can fix.

My conclusions after having owned many Macs since 1985 is that they never fail. So there.