Do you have a copy of your OFW nor bios backup? If so, try putting that on the micro sd card and flash using FLASH FUN option on e3 flasher (first switch up, the rest all down) i had the same exact problem as you, and i solved it (i have a fat Ps3) sometimes, the downgrade process gives you a YLOD, and you may also need to solder the SBCE point from your e3 flasher to the nor Tristate on your ps3 motherboard. Good luck buddy
Sent from my LG-MS910 using Tapatalk