Ok, some tests and some news!
Removed all ram, insert only 2 dimm's (64x2 A4/B4). No chime, but the screen appear very fast... 10/20 seconds, is clear the time of black screen is memory test, more memory, more black screen.
I removed all! Only 2 dimm's (16x2 A4/B4), removed all pci boards, restored 604 cpu. Boot from cd. Shutdown, boot.... chime ok!!!
Restored Sonnet G3... no chime! But boot very fast.
Restored 604, chime ok.......... Sonnet kill my chime!!!
Restored all my ram with cpu 604, chime ok, 45 seconds of black screen!
Sonnet G3 vs 604 = chime or not chime, no other difference
At this time i think 45 seconds of black screen at first boot is normal, is ram related... Mac run at first boot a full memory test, memory is so much and the time is long.
The conclusion is: I reinstall G3, not listen the first chime and I wait 45 seconds at first boot

at least I understand why