Yeah this specific issue sucks to troubleshoot because sometimes the only way to be 100% sure it is the CPU is to have a exact same model CPU and throw it in and see if it works… I would isolate ram too, see if 1 stick works, etc.

Microsoft uses a combination of hardware IDs (specific components on the system with unique serial numbers) and an actual license key to ensure a device is licensed. This is how sometimes you appear to do a fresh reinstall but the drive activates without a key. You can still pull a traditional license key and it can usually be used to activate 2 distinct devices, but the actual licensing terms are pretty ambiguous in that they say you can only do one device but actually allow 2 or more. Sometimes replacing too many components and activating windows again results in the activation check.

The unfortunate truth is that your probably only going to get 2 years at max capacity, and about 6 years total out of a battery. Any more than that you should consider yourself on borrowed time.

More than likely it’s a lion battery and has its own battery management. The best way to retain the life of a battery is to allow the battery to go to 20% and then Recharge. If it’s primarily used plugged in, it’s good to do this once a week. The BMS should do 90% of the work of retaining the life of battery

standard 3.5mm cannot do both, the specification you could try looking for is 4 conductor 3.5mm...