You can try tuning off or unplugging the PS and using the CMOS discharge jumper to reset the CMOS. When you turn the PS back on, try rebooting the the computer while holding down the 'insert' key and keeping it held down. If it starts to post, pop in your 1.4 BIOS flash floppy while still holding down that key. Once in DOS type runme and hit enter. You should be able to reflash to 1.4.
If it just won't post, buy a BIOS rescue kit from ExcaliberPC for $15.