Apple IIGS and adb keyboard + mouse problem

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Apple IIGS and adb keyboard + mouse problem

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

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Me too!

Hi Philippe,

I've got exactly the same problem with one of my ADB keyboards, right down to the exact symptoms. At this point I think I'll need to replace the keyboard processor, and I have no idea if a replacement is available. 

(I've replaced the two capacitors and reflowed both connectors)

 

If anyone knows something I have missed, I'd love to find out!

 

Chesh

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Following...

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.

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What encoder chip do they use

What encoder chip do they use in those?  something like an 80xx microcontroller or something proprietary Apple?

 

Sadly either way it may be very difficult to find a replacement part.  However, you can find keyboards on places like eBay and there are converters like BMOW's to let you use a modern keyboard on an ADB machine.

 

Even if a keyboard is not repairable, don't throw it out!  The parts are valuable to repair other broken keyboards.

 

 

 

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An adb splitter would also

An adb splitter would also work but I suspect they’re pretty rare.

When I bought some 30 years ago, the clerk said that they only sold a couple a year.

 

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I'm not sure about Philippe's

I'm not sure about Philippe's keyboard, but mine is the Apple Desktop Bus Keyboard.

It's got an NEC 8048HC610 encoder in it.

I'd love to get it working again, as it has the same design language as my IIgs.

(I mean, it's not like I don't have 3 other ADB keyboards, but, y'know...)

 

Chesh

 

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The c0nnectors can wear out,

The c0nnectors can wear out, get loose, etc. Don't rule out the cable and connectors

Did you try to clean the contacts? Taks some really small cleaners and something like a deoxit or IPA.

 

You can try a s-video cable in place of the ADB cable to see if it's a cable issue.  

 

The erratic mouse behavior isn't as obvious beause ADB is digital so the behavior being odd is odd. 

Do you have access to a logic analyzer?  If so you can motherboard  signals, but I'd do in on pins 27 and 33 of the ADB Controller and see what you're getting for traffic.

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adb trafic check

Hello,

I clean the connectors with deoxydizer and then add a little drop of WD40 but no change at all...

I have a scope and a logic analyzer and can give a look to the adb bus.

You mean pins 27 and 33 of the 40 pins ic of the keyboard ?

Regards.

Philippe

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I managed to fix mine.

Turns out there was a hairline crack across the entire board.

Here I have removed the solder mask with a fiberglass pen to make it more visible.

Fixing this crack has solved the problem.

I also soldered on a fat capacitor leg saved from another project for more mechanical strength. I've also coated the area with a sealant (Aka nail polish) to stop it all oxidising.

Yay! Matching keyboard!

 

Chesh

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Good news on finding the

Good news on finding the solution.

 

ggb
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Keyboard model

Philippe what model ADB keyboard are you having issues with?

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Its a M0118.

Its a M0118.

 

I cant see the picture into previous post. Is it possible to post again ?

 

Thanks.

ggb
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Test ADB connectors

If you have two ADB cables, plug an ADB cable in to each end of the keyboard and measure the resistance between the pins on the two free ends of the ADB cables.
eg Pin 1 to Pin 1, Pin 2 - Pin 2, Pin 3 - Pin 3, Pin 4 - Pin 4, and round shield - round shield.
They should less than 2 Ohms between the pin pairs.

If there is an issue with one of the pin pairs, then remove the keyboard from the case and flip so the keycaps are facing down with the PCB up, check between each ADB daughter card that there is continuity between each ADB socket pin and the other matching daughter card ADB socket pin.
If no issues, then consider changing the ADB socket on the bad end.
If the keyboard works from one end, then the controller IC is working ok.

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Fixed !

Doing the continuity check like in the previous post I found a track on the right daughter board which look suspicious...

It was between the flat cable connection and the black square component (I assume a filter). Sometime ok, sometime not, press strong then contact, just touch no contact etc..

So I put a small wire over the track then... the keyboard AND the mouse works !

I can switch the left and right connectors without problem.

Note that even with a magnifier and a strong light I have not see any cut or bad soldering on the track... Just the ohmmeter show something strange.

Thanks to all for the help.

Regards.

Philippe

 

 

 

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CheshireNoir wrote:Turns out
CheshireNoir wrote:

Turns out there was a hairline crack across the entire board.

 

Your pictures don't show for me. I imagine you had a cracked trace? I've seen those often on monitors, but imagine it's totally doable with a keyboard connector too when some trips over the cable or similar.

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Wawavoun wrote:Doing the
Wawavoun wrote:

Doing the continuity check like in the previous post I found a track on the right daughter board which look suspicious...

It was between the flat cable connection and the black square component (I assume a filter). Sometime ok, sometime not, press strong then contact, just touch no contact etc..

So I put a small wire over the track then... the keyboard AND the mouse works !

 

 

 

Nice work! Now after those two bad trace things, I think I have something to dig into!You were correct on the previous comment, I was talking about the ADB Controller chips (sharing in case someone else finds it useful):
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