Corruption is common in this era of IdeaPads. Use a programmer like the RT809H or TL866II to re-flash the SPI chip with a verified dump.
Typical diodes in this block are high-voltage types (BA582, or multiple SS14 in series). bm5291 ver 1.3 schematic
If you have a Ver 1.2 schematic, do not assume it is interchangeable with Ver 1.3; the feedback network and enable timing differ. Corruption is common in this era of IdeaPads
: The BIOS ARCHIVE Telegram channel maintains a large collection of original laptop BIOS and EC firmware dumps, which are often used alongside schematics for full board recovery. Essential Repair & Diagnostic Steps bm5291 ver 1.3 schematic