Lenovo Lenovo G700

Lenovo G700 HM70 – Attempt to bypass the 30-minute Intel Core CPU limitation​

Hardware​

• Laptop: Lenovo G700
• Motherboard: Bambi v2.0
• Chipset: Intel HM70
• Original Intel ME: 8.1.2.1318 (1.5 MB)
• Tested CPUs:
  • Pentium – works correctly
  • Core i3 / Core i5 – system resets after approximately 30 minutes

Analysis​

Both SPI flash chips (2 MB + 4 MB) were dumped and merged into a complete 6 MB image.

ME Analyzer reported:

• Intel ME 8.1.2.1318
• SKU: 1.5 MB
• TCB SVN: 1
• Valid and complete ME region

The image was successfully opened using Intel Flash Image Tool 8.x.

Modifications performed​

1. Full backup of both SPI flash chips was created.
2. Original Intel ME 8.1.2.1318 region was replaced with:
   • Intel ME 7.0.4.1197
   • 1.5 MB
   • PRD RGN
3. A new BIOS image was built using Intel FIT 8.x.
4. The resulting image was verified with ME Analyzer:
   • Intel ME 7.0.4.1197 detected successfully.
5. The modified image was processed with me_cleaner:

py me_cleaner.py -S mecust.bin

1. me_cleaner:
   • removed most Intel ME modules,
   • preserved the required BUP module,
   • set the AltMeDisable (HAP) bit,
   • kept the FTPR RSA signature valid.

Result​

After flashing the modified image, the laptop successfully booted and started running MemTest.

Long-term testing is in progress to determine whether the modification eliminates the approximately 30-minute reset behavior when using Intel Core processors.

Disclaimer​

This modification is experimental and performed entirely at the user's own risk. A complete backup of all SPI flash chips should be made before attempting any changes.