Amiga A1000 repair

[cjr]

so, I have an A1000 here and can't seem to get many signs of life out of it.
the POST seems to cycle through grey, white, yellow
there are some warbling tones played when it changes from grey to white, then the floppy seeks, then screen changes to yellow, and it restarts back at the beginning.
According to http://en.wikipedia.org/wiki/Power-on_self-test#Amiga_POST the yellow means "CPU Exception Before Bootstrap Code is Loaded" but I'm not sure if that just means it couldn't kickstart, or if it's more serious.
To eliminate floppy disk/drive issues, I'm booting what I hope is a good kickstart image from an HxC floppy emulator (which I've tested in an A500 first so I know it works), no change.
Removed the 256K ram pack off the front, no change.
Removed the DKB Insider (http://www.amiga-hardware.com/showhardware.cgi?HARDID=990), no change.
I'm about to try and another 68000 (if the A500 one is socketed I can rob it) and will post an update if that changes things.

so, who remembers (or has one working) the A1000 POST and expected behavior?

Any tips appreciated.
Chris.