On 30 Jun 2012 at 16:37, Ryan Brooks wrote:
Normally, it would make a bong sound each reboot, but
if it is getting
the the booting screen, it is not receiving the keypress/not acting on
it. You sure on the C-O+P+R key combo?
With cmd+option+p+r pressed, the screen cycles between grey and
black. When released, the "Welcome to Macintosh" boot screen comes
up. But nothing happens, otherwise--the speaker is still silent.
Can you get into open firmware as others have
suggested?
Well, you have me there. I didn't think that NuBus Macs had open
firmware. At any rate Cmd+option+O+F is completely ignored. But if
there's Open Firmware on that machine, I'd appreciate knowing how to
get to it.
And this is different than a PC motherboard how?
Let me
(reliably) reflow that BGA that I can buy where? Data sheet?
I can find datasheets for most PC chipsets of the 6100's vintage
(1994) and at least know what signals to look for. On the Apple, not
so much. I don't replace BGAs (but I know people who do) but I have
replaced QFPs without serious issues--and the ones on the 6100 aren't
particularly fine-pitch, so they should be a walk in the park to
change.
So where are the Apple datasheets on the 4 largish 124-pin QFPs on
the 6100? Surely, Apple can't be worried about IP on a nearly 20
year old design...
--Chuck