Probably throw it away at this point.  You can try clearing the NVRAM using the jumpers on the motherboard, but if that doesn't work, and you can't get back to a point where you can try reflashing the BIOS, then the board is useless.  The post you found that in most likely also had some warning that unsupported flashing could "brick" (ruin) the board.
Hi, I have bought a used PE1950 over the Ebay. The machine has a custom BIOS, which I tried to update to 2.7.0 under DOS, but not worked. I have found a forum message, try to use the -forcetype command line switch.No problem, do it. The updater correctly erase the flash(!), wrote anything to it, verify and the said: Press any key to reboot. I have pressed. Since then the machine display on the dignostic display: E1410 System failure, and the coolers periodically spin up then down.Maybe some watchdog circuit reset the machine periodically. Do I have any chance to repair the BIOS, or throw away the motherboard? Thanks Zoltan
How can I repair an erased BIOS?