phase 5 blizzard iv 1230 64 mb not booting up

[dougal]

Just a shot in the dark here, but does your A1200 have the "timing fixes" ?

Did you have an accelerator before ? Did it work well ?

Is your A1200 a Commodore A1200 or Amiga 1200 from Amiga Technologies ?

You could also check that the edge connectors of both your A1200 & Blizzard are clean. If you have a PCC cleaner try cleaning the edge connectors.