Bought a new 300W PC-PSU for me A1200, switch the +5 and +12 by mistake. I was not looking on the manual carelessly. Switch on. !!>poof
It took me a month to find a new mobo. The replacement mobo was an Amiga Inc. My old floppy(1.76MB) didn't work. I had to re-wire the mobo for the old floppy to work. I found a shcematic of the connection to make the panasonic drive to become high dens. Instead, I followed the comparison of the original C= design. Switched on. It booted. Worked since. Wheew! :-)
