IIe Boots to System Diagnostic

4 posts / 0 new
Last post
Offline
Last seen: 1 month 1 week ago
Joined: May 9 2021 - 15:23
Posts: 2
IIe Boots to System Diagnostic

I have a IIe which always boots to the system diagnostic (garbage screen followed by "System OK"), no beep.  My understanding is that this is traditionally caused by either a bad keyboard connection or a stuck key.  However, I've tried:

  • Replacing the keyboard with a different one
  • Reseating both ends of the keyboard cable, replacing the keyboard cable with a different one
  • Trying the keyboard and cable in another IIe (they work fine)
  • Mashing the keys a while to toggle any that might have been stuck
  • Removing all expansion cards and trying the above steps

With no luck whatsoever.  The machine still boots to the system diagnostic, and the keyboard appears responsive - its power light turns on and if I press the apple key after the diagnostic completes it goes back to the garbage screen.  What else could trigger this state?

 

More context: This machine has been working for quite some time.  Earlier today I installed a Mockingboard in Slot 4.  After that, I was hit with these symptoms.  After taking the machine apart, it started booting up again after I removed and reinstalled the keyboard, so I assumed the cable was loose on the keyboard side.  After I confirmed everything was working with all the expansion cards reinserted, I put the top of the case back on - and was back to booting to the system diagnostic.  I've removed the case and done all of the steps above with no luck - am I missing anything else obvious that could trigger the system diagnostic?

 

Online
Last seen: 1 hour 23 min ago
Joined: Jun 18 2010 - 13:54
Posts: 384
Anything plugged into the

Anything plugged into the GAME I/O (Joystick) port?

The diagnostics are triggered by the Open and Closed-Apple keys. While technically part of the keyboard, they are not handled like the rest of the keys through the keyboard controller chip. Instead, these keys connect to button inputs on the game controller port. Which means an errant joystick or other device plugged in there can also trigger the diagnostics.

 

Offline
Last seen: 1 month 1 week ago
Joined: May 9 2021 - 15:23
Posts: 2
Great catch!  I had forgotten

Great catch!  I had forgotten to disconnect the joystick.  After doing so, it boots fine.

Offline
Last seen: 10 hours 29 min ago
Joined: Apr 26 2016 - 08:36
Posts: 173
If that worked then the next

If that worked then the next step is to figure out what the problem is with button #1.

 

Log in or register to post comments