This file (boot_152.mid) can be used when only the lights go on after turning the OB-12 on. Read the manual 11.1 (p.240) before dumping, maybe you don't need this file.

E.Luciani, (Viscount technician) wrote to me:

Please try to update your synth with the attached file. This is a
fundamental section of OB12 internal software. So DON'T TURN OFF THE
INSTRUMENT and/or STOP THE UPDATE during the transmission data.
After this please proceed with the CPU update.