Ignition module

[sliller]

Does anyone know much about ignition modules?.
Ive got a '84 MG Metro engine in my mini, currently missing
any spark??. Tried a couple of coils with no luck ( yes there 12V getting to the coil), I now suspect the distributor/amplifier module. What should I get out of it?, tried looking at the output directly out of the distrubutor, which is a kind of signwave, should the ignition module just give me a rectified spike?, how big?, how long?. Also how can I check the coil beyond resonable doubt?.
Any help or ideas much apprieciated.

[Mini1976]

My amplifier module packed up. When it did it it went from an intermiten fault, to not ticking over withour pulling the choke out and runing at atleast 2500 rpm and when it did drop below that the rev counter would go from 2400 to 0 instantly. Eventually (Within say a week) it just stopped working and had to fit a new one (£30). You cant fit second hand ones as you need the heat transmitting greese to keep it cooled and it only comes in a very small tube with new modules.