Arghh! , need some help here with my a1200!

[Castellen]

If you have a high speed digital storage oscilloscope you can get a lot more information, but I'm guessing you won't have one of those handy :-)

So the obvious test methods are:
Reduce the system hardware and software to the most basic level possible and see if the problems still occur.

Swap hardware components one at a time (CPU board, motherboard, power supply, cables, drives, etc) until you narrow the problem down.
Of course you shouldn't test with suspect hardware, only known good parts.  If you don't have spare parts, then maybe borrow some.

If you're running OS 3.9, make sure BB 1&2 are installed, which fix conflicts with some hardware.

Try using a clean install of WB 3.1.

[Castellen]

Something else I just remembered.
Are you using the square A1200 power socket (standard motherboard one) to supply power to the computer?

Especially with the additional current of the PPC board, the current through the socket is quite high, so unless the contact is perfect, you can get power supply issues to the motherboard.

Using a small spike, you can bend the "prongs" of each socket hole inwards, increasing the contact tension on the plug's pins.  Using electrical contact cleaner to remove corrosion and contamination can also help.