Re: Fatal Error $0911

[rubywand@aol.com (RUBYWAND)]

In article <smarti-0409961322050001@m22605-mac2.mitre.org>,
smarti@gwis2.circ.gwu.edu (J. Scott Martin) writes:

>....
>If anyone out there has the Apple Technical Repair manuals, or has more
>information about a "Fatal Error $0911" please post a follow up message. 
>I have checked both the Firmware reference (nothing in there about
>diagnostic testing) and the Hardware reference (nothing in there either).

>....

     We nailed the source of this problem years ago in Computist. Most
likely, you have a malfunctioning ADB Controller IC. Many early IIgs's
were shipped with the faulty IC and it has plagued users of these machines
ever since.

     A number of tests demonstrated that the faulty ADB IC's tend to
glitch over a fairly narrow range of temperatures. Typically, glitching
occurs at slightly below normal room temperature.

     The only known genuine fix is to replace the IC (which, naturally, is
soldered to the motherboard).  A relatively easy cure is to tape a small
bulb (powered by the unused +12V fan pins at the back of the motherboard)
to the IC. Duct tape can be used to create a mini-oven.  Once you get past
startup, the bulb quickly warms up the ADB IC and prevents further bombs.

     A check of the IIgs schematic indicates that there may be an
alternative fix; but, it would involve some hardware mods.

     Try the bulb. It should reduce bombouts, especially post-startup
bombs, to near zero.
     

Rubywand