Apple ][e keys not registering

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Apple ][e keys not registering

  I have been working on one of the original ][e computers (white keys).

There are several keys that just will not register no matter what I have done.

Here is a list of what I have done.

   I have replaced all the ][e enhancment chips - which someone else put in, with the original chips.

   Replaced keyboard rom

   Replaced memory with new

    Replaced keyboard with known good keyboard

    Re-flowed solder on the back of keyboard connector and checked for cold solder and traces

    Cleaned keyboard connector pins

Still have the same characters not responding.

Is there something I am missing?

 

    

 

 

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Which keys don't register?

Which keys don't register?

 

Did you check the socket of the keyboard encoder chip?

 

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Apple ][e keys not responding

 The keys that do not respond on either keyboard are the same:

  5 6 DEL T V \ G J R E T N M UPARROW ~

The socket for the keyboard rom has been cleaned and looks good

I tried another keyboard rom and it did not solve the issue either.

Thanks for any assistance in this issue.

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orlandoave wrote: The keys
orlandoave wrote:

 The keys that do not respond on either keyboard are the same:

  5 6 DEL T V \ G J R E T N M UPARROW ~

The socket for the keyboard rom has been cleaned and looks good

I tried another keyboard rom and it did not solve the issue either.

Thanks for any assistance in this issue.

 

I see a 8 byte pattern where bits 0 and 1 are missing that are needed for many, but not all, of those characters.

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There must be some chip or

There must be some chip or component causing the issue.  Something the kernal does not pickup.

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All of the bad keys connect

All of the bad keys connect to the Y5 and Y6 inputs of the Keyboard Encoder. When you said that you tried a different keyboard, did you mean that you plugged in another keyboard to the motherboard socket?

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It may be more wide spread than that...
jeffmazur wrote:

All of the bad keys connect to the Y5 and Y6 inputs of the Keyboard Encoder. When you said that you tried a different keyboard, did you mean that you plugged in another keyboard to the motherboard socket?

 

Here is a keyboard Yn, Xn matrix for the IIe keyboard and keypad.  Y7  & Y6 related keys are indicated 7 times for the keys mentioned that do not respond, Y3 - 3 times, Y4 - 2 times.  X1 - 4 times,  X3 - 3 times,  X2 - 2 times, with other combinations less.

 

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