Re: Did my Apple iiGS Die?

[Michael J. Mahon <mjmahon@aol.com>]

kynrek <kynrek@gmail.com> wrote:
> On Nov 20, 1:03 am, "ict@ccess" <gids...@sasktel.net> wrote:
>> On Nov 19, 10:11 pm, kynrek <kyn...@gmail.com> wrote:
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>>> On Nov 13, 5:53 pm, "ict@ccess" <gids...@sasktel.net> wrote:
>> 
>>>> On Nov 13, 8:15 am, kynrek <kyn...@gmail.com> wrote:
>> 
>>>>> On Nov 13, 6:13 am, "ict@ccess" <gids...@sasktel.net> wrote:
>> 
>>>>>> On Nov 13, 1:30 am, kynrek <kyn...@gmail.com> wrote:
>> 
>>>>>>> On Nov 13, 1:25 am, Vladislav Korotnev <vladkorot...@gmail.com> wrote:
>> 
>>>>>>>>> Whiew!! Thanks guys, I will have my wife test when she gets home (I'm
>>>>>>>>> out of town on business) I'll let you know how things turn out.
>> 
>>>>>>>> So, were you able to test it?
>> 
>>>>>>> Ok so unplugging all cables including keyboard except monitor did not
>>>>>>> help. Removing ram card did not help cleaning the motherboard did not
>>>>>>> help. Oddly enough if I plug my serial to USB adaptor into the 9pin
>>>>>>> game port the system will boot! Is the screen supposed to have a blue
>>>>>>> background? I want to fix the problem but I'm still clueless as to why
>>>>>>> this fixes the problem. I have the motherboard removed from the case
>>>>>>> and don't see any obvious issues. Any ideas?
>> 
>>>>>> A blue screen happens when your computer gets reset to its factory
>>>>>> defaults.  If you can boot with the serial to usb adapter, hold down
>>>>>> the option key before power on.  If you are able to get into the
>>>>>> control panel, you can check the settings.
>> 
>>>>>> Did you have anything plugged into the game port when previously
>>>>>> booting?  A way to check if the computer is sensing if the paddle
>>>>>> buttons are being pushed even when there is nothing plugged in is to
>>>>>> go into the system monitor with a "CALL -151" and type C060 or C061 at
>>>>>> the the star prompt.  Any value greater than 80 indicates that the
>>>>>> paddle buttons are in its pressed state.
>> 
>>>>>> Rob
>> 
>>>>> Ok I confirmed it was set to blue in the control panel
>> 
>>>>> I ran c060 multiple times wile the adapter was plugged in and got:
>>>>> FF
>>>>> 80
>>>>> A0
>>>>> A0
>>>>> FF
>>>>> 80
>>>>> A0
>>>>> A0
>>>>> 80
>>>>> A0
>>>>> A0
>>>>> 80
>>>>> E2
>> 
>>>>> Then unplugged the adaptor and got:
>>>>> A0
>>>>> 80
>>>>> 80
>>>>> B0
>>>>> A0
>>>>> 80
>>>>> 80
>>>>> 80
>> 
>>>>> C061 with adaptor:
>>>>> 20-{
>>>>> 20-L
>>>>> 00-.
>>>>> 20-.
>>>>> 20-
>>>>> 30-r
>>>>> 20-
>> 
>>>>> C061 without adaptor
>>>>> 00
>>>>> 7F
>>>>> 00
>>>>> 00
>>>>> 20
>>>>> 20-1
>>>>> 00
>>>>> 00
>> 
>>>> My mistake.  The address was supposed to be C062 instead of C060.
>>>> C061 is the softswitch for the Apple key which will go high ($80 or
>>>> higher) when pressed and C062 is the Option key.  You can test this by
>>>> holding the Apple key or Option key down on the keyboard just after
>>>> typing in the address and before pressing the Return key.
>> 
>>>> Since C061 shows a low number ($7F or lower), (a high number is needed
>>>> to cause the self test to start), neither the keyboard or the adapter
>>>> seems to be the cause of the self test.
>> 
>>> C062 is giving the following readings
>> 
>>> ff
>>> ff
>>> ff
>>> ff
>>> ff
>>> a0
>>> a0
>>> 80
>>> 80
>>> a0
>>> a0
>>> a0-6
>>> a0-.
>>> a0
>> 
>> A high number ($80 or higher) indicates that the computer is sensing
>> that the option key is being pressed or held down or a paddle button
>> is pressed.
>> 
>> You did unplug all devices including keyboard and joystick/paddles and
>> remove all cards with your last boot up test, correct?
> 
> Yes. Can anyone suggest which component to replace? Ic, capacitor,
> resistor? I'm handy with a soldering iron but don't know which
> component to replace. I posted pictures of the motherboard earlier in
> the thread.

Unfortunately, it is much less likely for passive components connected to
an input to fail than active components. The chip connected to that input
is a more likely problem--unless something is shorting that input. 

-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon