Franken-15"-Macbook Pro 2015... stuck on fresh install

Felipe_Olivares wrote:

The replacement of parts (and resetting SMC) resulted in:

Machine boots with a startup USB drive with Mojave install; 

4. I can erase the SSD and go on to install Mojave; the machine behaves pretty smoothly

1. Trackpad, speakers, keyboard, wifi, etc. work fine

I can see the battery is charging now and can see now a % of charge, 1. however machine powers off if a pull the AC adapter

Usually this indicates an issue with the battery or the DC-In Board. It has been years since I have encountered this issue with one of our organization's Macs so I may not be remembering details correctly, but it definitely indicates a power issue somewhere.

1. After the machine restarts/resumes, it hangs at "12 minutes to complete the installation"

This could indicate a power issue of some sort as well and can definitely occur when the battery is disconnected. When Apple laptops experience any sort of power issue the CPU may become throttled to idle speeds (800MHz) so everything can take an extremely long time to finish. When this happens with a USB-C Mac I will sometimes give up trying to boot macOS because it literally can take hours to finish booting normally. A bad temperature sensor could also cause the system to become throttled, but the fans would also be running at high speed.

Considering all the parts I've replaced, I am puzzled as to what could be wrong with this Franken-Macbook.  Don't know what else to try.

When changing so much it can make it difficult to figure things out especially when you are dealing with a completely unknown system from eBay. Don't discount the Display causing a problem or one of the remaining eBay components since it just needs to affect the power of the Logic Board.

You always run the risk that one bad part can damage a second part so when you begin swapping parts between a known good system and the broken eBay laptop you run the risk of damaging your known good system/part(s) when reinstalling its original formerly known good parts. While thankfully this is rare, it has occurred enough times that it is always something to consider.

If you restore all the formerly known good parts to the original formerly working laptop does everything function like it did before? If not, then I would cut your losses and recycle all of the parts involved (both the eBay laptop and the original formerly known good parts including any others you purchased and used on this system) since you may damage another system by using those parts. If all the original donor parts still work in the original laptop, then you can continue trying to figure out this puzzle.

Felipe_Olivares wrote:

After the machine restarts/resumes, it hangs at "12 minutes to complete the installation"

This could indicate a power issue of some sort as well and can definitely occur when the battery is disconnected.

Is there a way to diagnose the issue? Using now new Magsafe board so don't know what else to check. For what is worth, I am using a logic board that I pulled from another working 15" Macbook Pro 2015.

You can run the Intel Power Gadget to see if the CPU Frequency is above idle (typically 800MHz) and how much power the CPU is using. Usually if the laptop is being throttled due to a power issue the CPU doesn't get hot (it will be warm).

https://software.intel.com/content/www/us/en/develop/articles/intel-power-gadget.html

I've seen the Trackpad issue you describe with some of our organization's Macs, but I'm not sure why it occurs unless the user does have a Bluetooth mouse/trackpad and macOS is just complaining that it cannot be found. After some time or after another reboot the Trackpad System Preferences can be accessed normally.

I'm not sure about the amber charging LED. I forget if that is normal behavior when the battery is disconnected.