ThinkPad

Recently I decided to update my coreboot, with some config changes. It worked, but after I put my laptop to sleep it doesn't boot anymore. (Power LED and fans turn on just for a second)

I tried disconnecting it from power, including the small bios battery. Still the same result. Tried to flash the previous version that worked — no result.

IIRC I compiled it with "Stage Cache for ACPI S3 resume" = "CBMEM". If it's related, how do I clear CBMEM?

Any advice that doesn't require soldering or repeated (dis)assembly?

UPD: Tried stock bios, no result :(