MBP( mid 2015, OS Monetary 12.71.1) restarting in loops and comes back in user login page. safe mode not coming up. Force switch on with recovery keys not helps.

Also please check this post with clear alerts, my lines and images.

What if MBP FAILS to startup in safe mode… - Apple Community

Thanks much for asking all points in order help me better. It is needed as multiple failures happened.

I have a TM back up around 2.5 months back. But post that loads of hardwork and imp data r there. I can’t make up those again by extra efforts. It will b big loss for me going ahead.

Unfortunately I don’t have another working max w me. Though I have a similar one with broken screen. I just taken its batteries yesterday to replace with this one. As its batteries bulged so Apple local support center told to change batteries. But bad luck, exact same issues of restarting back to user login screen.

the spare laptops motherboards hard disks r fine. But if I replace I will be losing data. Because of screen issue I can’t use it as an ext as u though of. ( Target disk mode? )

May be I need to seek out for any help who has time n mind. Very hard though.

I’m yet to check Apple Diagnostics. Will update here.

Tried to do safe boot in two ways. But looping back to user login screen. Safe boot mode might help but pressing shift keys not working.

what to do here time being?

A pop up saying that it can’t be unlocked. But not asked for any credentials or any action from my side before showing this!!!! Also I don’t understand the line on left side of the “Unlock” button. That’s another topic though to discuss.

here is the popup ( green marked )

Yes I could run d Diagnostics successfully. It shows no issues found!!!!

what does that mean in context to my sufferings?

Now next I did is click “Get started ->” for more info.

it asked to select wifi. Selected with d wifi password.

then surprisingly macOS recovery asst appeared.

upon giving Apple credentials on request it showed ‘recovering file vault key’ which I have NOT asked for!!!!

and I knew immediately what is coming next as faced few times already in last few days -

I just shut it down now with frustrations which rarely happens in me except this Apple design fault in file vault issue.

Ideally as per d guidelines-

“To get information about your service and support options, make sure that your Mac is connected to the internet, then click ”Get started” or press Command-G. Your Mac will restart to a webpage with more information. When you're done, choose Restart or Shut Down from the Apple menu.”

but in my case, it is not restarting with a webpage even though asking for wifi again and it’s password. Globe started spinning, but it’s calling macOS reovery asst instead as shared in last reply.

How can I fetch the Terminal window

to enter…

    fdesetup status

    diskutil cs list | grep 'Conversion Progress'

Last one no half hour tried several ways to see an opportunity to pull it for any submenu at top left corner. But failed.

I highly appreciate your efforts to help, even possibly at ur odd times too.

What the result will be by using a new hard drive? Whole Motherboard replace not needed I guess ?

I’m trying to understand what does that error msg mean!? Does "No CoreStorage logical volume groups found" indicates that d system couldn't locate any CoreStorage logical volume groups? What is coreStoage!!! ?

if d issue with the disk structure or file system, but does it necessarily mean my data is irretrievable?

U can catch it instantly by recalling other errors n screenshots. But I can’t map.

(Apples uses lots of terms n techniques for good but confuses users w/o immediate help symbols. )

does the scenario means also I can’t save my data at all? Internal disk is corrupt ?

Does reset NVRAM/PRAM etc could help here ?

does reinstalling OS now might rewrite /corrupt internal data if any hope is still there?

I'm minimising my concerns now but I had to ask above few at least.

I Dont to want to burden to one person but other experts may also contribute to save my data, if possible.

Thanks for all efforts. 🙏🏼

With few of concerns in mind, and about saving my data, it seems I hv to let it go. So i will try for next 14-16 hrs to understand what is best to be done before knocking a service Center if sw ways can’t help me.

But still I highly appreciate both experts BDAqua and Grant Bennet Alder’s helpful guides and genuine efforts.

I’m still hoping through them it gets d cure. Or point out the perfect hw issue to take physical action. ( money matters) Will be trying still next 15 hrs with all the guidance, with rest.

Sorry BDAqua, I hv missed to see ur last to last response here. But thank u both so much.

I will try to install from an ext drive after few hours of try again. Never done so. Not sure if steps. Any support topic ( preferably w images ) ?

im not clear with “..until we get a working install on an external drive”. Sorry to bother.

OS version was 12.17.1 I think