I got pretty much the same brick but on my NAND PS3 that was on 4.21 REX. After hitting Boot OtherOs in the toolbox by accident my PS3 rebooted after exiting it and now it just turns on with green light, no beeps no video. And recovery menu doesn't work I was in DEX Mode I believe when i hit the boot otheros option in toolbox menu... I have a PSP and an android phone, can this help me undo this semibrick???