Also, you may want to open your A1200 and see what revision it is.
Go to
http://amiga.emugaming.com/qa.html and search for the section
I have heard that some A1200's have problems with PowerPC cards. How do I know if my Amiga will have problems and how can it be fixed?"I had a similar problem with my CSA 12 Gauge fitted. Would only turn on around 1 in 10 goes. Then I did the mod (for Rev 1.D.4 which I have) and all is good, running on standard A500 PSU
