Ok, so I have managed to find my way back into the apple collecting hobby accidentally. 
I have since aquired an Apple IIgs that when I turn it on, I get Fatal System Error 0911. I know that the error has to do with ADB. I am going to try the lightbulb over the ADB chipset trick. I also have checked all the PSU voltages and they are within half a volt. Have I missed anything? The machine in question appears to be a ROM 0 upgraded to ROM 1, and I have tried it without anything else connected, and the memory board removed. Anything else?
Apple IIgs Fatal System Error 0911
April 25, 2015 - 4:26pm
#1
Apple IIgs Fatal System Error 0911
gobabushka,
How do you have your keyboard and mouse connected to the unit?
Mouse to Keyboard to unit?
Keyboard to unit and mouse to unit?
did you check the battery?
Steven
I completely removed the battery to no effect. I also am running it with no keyboard even connected. Does it have to have a battery, keyboard, and mouse connected? I am getting about 11.73v from the 12v rail on the power supply. Is that out of tolerance?
Does anyone know what this code indicates?
Steven
Just to explain some keyerrors:
The IIGS requests for correct startup
at least a keyboard installed to press the option key while power on...
and enter the option panel ....
this may be accessed before the IIGS starts searching for a Boot device......
Within the option panel you may correct time and date if the onboard Battery is empty and that
will trace time till next power off and then time and date must be set again till battery is replaced by working item...
also you then will be able to set the slots and the boot device
choosing either the internal port of diskdrives at the rearport
or switch to Disk II Interfacecard in slot and set that slot to "your card"
as well as specifying if slotscan is to be performed while booting or if
Bootup is fixed to one specified slot....
unless this keyprocedures have not been performed you will only stumble from one error code to next error code...
If keyboard is connected and errorcode remains - then checkout ADB cable and keyboard....
unless you can´t enter the option panel - it´s just waisting time if you try to
jump across the line to later booting stage...
next errors with basic configuration but without booting device should result
from IWM chip ...
( no boot device,
bad device ...
or other alternate error codes...
by the way
if you want to seriously test the computer and its devices
its recommended to download image from IIGS Testing disk.....
http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Computers/Apple%20II/Apple%20IIGS/Disk%20Images/
speedyG
The 911 error indicates a timeout error while trying to talk to the keyboard micro and could be either the keyboard micro or the kbd glu chip that is at fault on the system board. Having a keyboard connected or not, makes no difference.
GeoffB
Error....
some of the timeouts result from faulty setup in option panel ( keyboard or mouse ) and
may disappear after correction of the setup at the option panel....
speedyG
OK. I tried powering on the IIGS with option held down. Same error. It will not seek any floppy drive that is connected on startup, just go to the error screen. What can I try next?
Apple //GS ROM 01 boots fine without connected keyboard and mouse!
Keyboard and mouse both work just fine on a Quadra 700 and a PowerBook 3400c
So then it's probably the logic board then. That sucks...