Chosen Solution
I recently replaced the fan on my MBP. I purchased a used fan from ifixit and swapped that because mine was REALLY noisy. Then about a week or so later this started to happen. The blue light on the front still blinks slowly, I have to force shutdown the machine, but the screen goes blank and nothing happens. No noises from holding buttons or anything. I’ve tried all of the different resets I can find. I’ve swapped in a different HDD. I have no idea what else could be causing this.
At this point I think you need to dig a bit deeper diagnostically. How about downloading these two apps: CoconutBatteryTG Pro Let see what they report. Paste the full main screens of both here for us to see.
Did you tried booting your Mac in Safe Mode? Also, I will advise you to run Apple Hardware Test to determine a failing Mac component. I am not saying this 100% but the fan might be a problem. Might Be. You better run First Aid and AHT quickly. Keep us posted
