Questions about Apple IIGS and adb bus

[Wawavoun]

Hello,

I have some problems getting a mouse working on a Apple IIGS.

The keyboard has two adb connectors one to the left, another to the right.

First I notice that if I connect the keyboard to the cpu with the left connector it works. He dont work if I use the right connector.
Its my first contact with a IIGS so I say to me its strange but okay...

Then I connect a mouse (works well on my Powerbook 100), of course to the right adb connector. The mouse work (move if I move it) but also do over reaction and erratic movements and is unusable.

The reverse configuration (uc to the the right adb and mouse to the left abd) give no result. Nothing works, mouse and keyboard.

Last : the mouse alone one the cpu adb port is working well.

I assume the problem is in the keyboard.
I check the continuity of flexible links of the two adb daughter boards and everything look good.

Any idea of what can I check now to try to find the problem ?

Thanks and regards.
Philippe

 

[CC_333]

What happens if you wiggle the mouse plug in the right keyboard connector? Does it feel looser than the left connector? Does the mouse's behavior change?

I suspect maybe loose solder joints for the right ADB connector might be your problem, or perhaps, but less likely, a faulty connector.

Anyone else?

c

 

[bibilit]

I agree with CC_333 loose or broken joints on the adb connector of the keyboard, an easy job, pretty common.

 

[Wawavoun]

Thanks for the advices.

Reflowing the adb connectors welding and/or trying to move the mouse plug give no result. The problem is still here.

A test with a Apple Extended Keyboard II and the same mouse show everything is ok so the problem is for sure in the keyboard.

 

[Wawavoun]

Fixed !
On the right small daughter board the ohmmeter show strange measurements (not short but not open, short if pressing strong, open if just touch etc...) for a track between the square black component (I assume a filter) and on of the pad connecting the flat cable to the main keyboard pcb.
Adding a small wire over the track and everything works well !
Note the nothing was seen even with a magnifier and a strong light. Only the ohmmeter show the problem...