Identifying a defective RAM IC on laptops with soldered memory
4 days ago
- #RAM Repair
- #Microsoldering
- #Memtest86
- Article discusses identifying defective RAM ICs on laptops with soldered memory, using a MacBook Pro Late 2013 15" as a case study.
- Warns about uncertainties due to lack of official documentation and potential other causes like PCB or CPU faults.
- Explains memory architecture: 8-bit data bus per IC, 64-bit width requires 8 ICs, two memory channels, two ranks per channel totaling 32 ICs.
- Describes using Memtest86 to identify failing bits, noting differences between Memtest86 and Memtest86+.
- Details decoding memory addresses to identify channel and rank, referencing a research article for reverse-engineered mappings.
- Steps to identify the affected IC using schematics and boardview tools like OpenBoardView.
- Process of replacing the defective RAM IC, emphasizing the need for microsoldering skills.
- Confirmation of successful repair via Memtest86 and Apple Service Diagnostic EFI.