Chosen Solution
I have a Macbook Air 2010 11” that boots to a ? folder all the time. I did all the normal things to try to come to a solution and all have failed. Reset smc, Pram, even booted into an external drive and ran disc utilities and found that the internal drive is seen, but there is no start up disc. So I played around a bit with the logic board and found all circuits from the Sata sector of the MCP to the SSD were ok. I even checked the PCI circuitry and all is good there. The one thing I noticed is that the MCP area on the board is getting very hot to touch 145 degree F, as compared to a known good board which is 125 degrees F. Could this be a bad MCP? Any thoughts would help? Thanks!
To start with the blinking Question mark is the system looking for the drive to load the OS. So do you have either a mounted drive internally or an externally? Is it running the OS version this system supports. I would use a macOS Sierra (10.12.x) bootable drive as using High Sierra (10.13.x). The highest this system can support (High Sierra) may not work as the systems firmware may not be able to work with the newer APFS file system. Using the Option (⌥) key you should be able to select the external drive using the Startup manager. Reference: Mac startup key combinations I’m not sure I understand your TLA MCP term. Its best not to use your own TLA/FLA’s as most people won’t know what you mean technically there is no Multi-Chip Package on this logic board. If you are referring to the CPU or GPU chips just call them out. I’m guessing your CPU is running hot as its stuck in a loop looking for that boot drive. Update (02/24/2021) Ah! You have a mismatch issue! El Capitan is HFS/HFS+ based, High Sierra and newer are APFS based. Your systems firmware was upgraded during the macOS High Sierra install to support APFS volumes, so its having issues with the older HFS/HFS+ drive. And/Or the SSD you installed is a AHCI/NVMe drive instead of a mSATA which your system requires. Make sure you are using an mSATA drive internally. Review this great guide The Ultimate Guide to Apple’s Proprietary SSDs
