Apple II GS Keyboard not working.

[zanglucarson]

Hi all,
I'm note entirely sure if this is the right place for this, I've been having trouble finding places to ask about this stuff other than reddit.
Anyways, my Apple II GS has recently developed an issue where the keyboard has stopped working entirely. I have no clue what could have caused it, about a week ago it was working fine, but I came back to it, and now it's not displaying any inputs. I tried booting into GS-OS, and while it boots fine, the cursor is unusable, as the keyboard and mouse are on the same circuit.
Anything helps, whether it be help for the issue or some good direction as to where I can find help, I've tried to sign up for applefritter but their registration servers appear to not be working at the moment.

 

[m1maverick]

About the only suggestions I can offer is to try and locate another keyboard and give it a try. Since the IIgs uses ADB you can use a keyboard from any Macintosh which uses ADB. Alternatively you can try your keyboard on any Macintosh that uses ADB.

If it's not the keyboard then I would suspect something has failed on the system board. One thing I would have you inspect is the battery to see if it leaking. If so cut it out of there immediately. If not you may want to think of removing it before it does (assuming it's the original battery). If it is leaking that could be a reason for the keyboard failure.

 

[za9ra22]

Is there any possibility that you had attempted to plug the ADB cable from the keyboard into one of the other connectors on the GS? The reason for the question is that some of the ADB keyboard models have a surface mount 'fuse' on their circuit boards that can be blown by the cable being connected to a serial port, for example.

Assuming that the GS boots, you may be able to test if it is the GS or the keyboard at fault by removing the keyboard, and connecting thee mouse directly to the GS. If the mouse works like that, it would strongly suggest the GS is OK, and the problem lies with the ADB cable itself, or the keyboard.

 

[zanglucarson]

I completely forgot to mention! I just swapped the battery for a fresh one.
I'm checking the board right now, it turns out that I think one of the solder pads on the board came off while I was swapping it..

 

[zanglucarson]

Is there any possibility that you had attempted to plug the ADB cable from the keyboard into one of the other connectors on the GS? The reason for the question is that some of the ADB keyboard models have a surface mount 'fuse' on their circuit boards that can be blown by the cable being connected to a serial port, for example.

Assuming that the GS boots, you may be able to test if it is the GS or the keyboard at fault by removing the keyboard, and connecting thee mouse directly to the GS. If the mouse works like that, it would strongly suggest the GS is OK, and the problem lies with the ADB cable itself, or the keyboard.

I've tested just the mouse as you said, still no luck unfortunately.
I think I have plugged the keyboard into the serial port by accident once or twice however.

 

[zanglucarson]

About the only suggestions I can offer is to try and locate another keyboard and give it a try. Since the IIgs uses ADB you can use a keyboard from any Macintosh which uses ADB. Alternatively you can try your keyboard on any Macintosh that uses ADB.

If it's not the keyboard then I would suspect something has failed on the system board. One thing I would have you inspect is the battery to see if it leaking. If so cut it out of there immediately. If not you may want to think of removing it before it does (assuming it's the original battery). If it is leaking that could be a reason for the keyboard failure.

I've made a jumper cable from the battery's clip to the point where the solder point would have gone to, the continuity seems fine, I tested it with a multimeter and it makes the connection.
However, still no luck.

 

[m1maverick]

I've made a jumper cable from the battery's clip to the point where the solder point would have gone to, the continuity seems fine, I tested it with a multimeter and it makes the connection.
However, still no luck.

Perhaps I wasn't clear. It's not that the battery may or not be making contact (or functioning). It's that these batteries have a tendency to leak a corrosive material onto the system board. This corrosive material can damage the system board and cause problems. Whether that's the case or not here I do not know but I recommend inspecting the battery to see if it has leaked. It might explain the issue.

Outside of that the best I can suggest is to try using the keyboard on a known working system and a known working keyboard on your IIgs. That will at least narrow the problem to the computer or keyboard.

 

[zanglucarson]

There is no visible leakage on the board, and the new battery and old battery both show no signs of leakage.
I'm afraid I don't have another system to test with.

 

[za9ra22]

I've tested just the mouse as you said, still no luck unfortunately.
I think I have plugged the keyboard into the serial port by accident once or twice however.

To be clear, if the GS boots and the mouse on its own doesn't work on the booted system, it suggests the ADB interface on the GS is the problem rather than the keyboard and/or the mouse.

I don't have any experience of the IIGS, but the troubleshooting steps are a matter of logical deduction to this point. As such, as the previous poster suggested, there could be an issue with the PRAM battery - or a previous one - leaking, and eating tracks on the board or contaminating essential components.

 

[zanglucarson]

To be clear, if the GS boots and the mouse on its own doesn't work on the booted system, it suggests the ADB interface on the GS is the problem rather than the keyboard and/or the mouse.

I don't have any experience of the IIGS, but the troubleshooting steps are a matter of logical deduction to this point. As such, as the previous poster suggested, there could be an issue with the PRAM battery - or a previous one - leaking, and eating tracks on the board or contaminating essential components.

As I stated before, there is zero sign that the battery in it before had leaked.
Here is an image of the board.

 

[MacTech68]

You might want to look directly at the ends of all the ADB connectors (on the ends of the keyboard and mouse cables) and ensure that all 4 pins are pointing straight at you.

The only other failure I'm aware of is the solder joints of the ADB sockets within the keyboard. There is quite a comon problem with at least one solder joint breaking. Obviously, re-soldering resolves the issue.

 

[m1maverick]

Interesting as my IIgs has a completely different battery configuration. You must have the ROM 3 version.

 

[zanglucarson]

Interesting as my IIgs has a completely different battery configuration. You must have the ROM 3 version.

View attachment 1763902

Yep! It's a ROM 3, it can be a pain since they're less common meaning that there's less support for them though..

 

[zanglucarson]

You might want to look directly at the ends of all the ADB connectors (on the ends of the keyboard and mouse cables) and ensure that all 4 pins are pointing straight at you.

The only other failure I'm aware of is the solder joints of the ADB sockets within the keyboard. There is quite a comon problem with at least one solder joint breaking. Obviously, re-soldering resolves the issue.

I highly doubt that the solder joints for both the mouse and keyboard would just stop working at the exact same time. I've checked the continuity of the wire, and found no issues. I've checked the continuity of the ADB port, no issues. Whatever this issue is, I'm nearly certain is something to do with the logic board.
Sorry if I sounded rude I'm just really frustrated with this issue.

 

[m1maverick]

Maybe provide a pic of the logic board around the ADB port? Perhaps we might be able to notice something out of place.

 

[zanglucarson]

Maybe provide a pic of the logic board around the ADB port? Perhaps we might be able to notice something out of place.

Here's a couple various images, please ignore my soldering job on the jumper cable, it was somewhat rushed. But it makes continuity if you're worried.

 

[zanglucarson]

Also if you're thinking it could be the ADB filter, I've already checked the continuity and it seems fine.

 

[m1maverick]

I don't see anything that jumps out at me. Unfortunately I cannot offer any additional troubleshooting suggestions.

 

[zanglucarson]

I don't see anything that jumps out at me. Unfortunately I cannot offer any additional troubleshooting suggestions.

Oh well, if you think of anything please let me know, thank you for trying to help.

 

[velocityg4]

While someone mentioned a fuse on the keyboard. I didn't find any mention of the motherboard.

Anyway's, after I recapped one of my IIcx. The keyboard and mouse wasn't working either. After much frustration and learning how to read a circuit diagram. I found it was one of the motherboard fuses. I forget which number but it was the fuse for the ADB ports.

So, I'd check the fuses on your motherboard. If you aren't familiar. They don't look like normal fuses but should be labeled with an F (F1, F2, &c). You shouldn't need to remove them. Just check continuity.

 

[zanglucarson]

While someone mentioned a fuse on the keyboard. I didn't find any mention of the motherboard.

Anyway's, after I recapped one of my IIcx. The keyboard and mouse wasn't working either. After much frustration and learning how to read a circuit diagram. I found it was one of the motherboard fuses. I forget which number but it was the fuse for the ADB ports.

So, I'd check the fuses on your motherboard. If you aren't familiar. They don't look like normal fuses but should be labeled with an F (F1, F2, &c). You shouldn't need to remove them. Just check continuity.

Can you send me a picture of what yours look like? I know they look different, but no-one's given me a proper example of what they actually look like
from what I've heard there doesn't seem to be one on the IIGS board, but there could be one in the desktop bus keyboard, I just don't know what to look for

 

[velocityg4]

Can you send me a picture of what yours look like? I know they look different, but no-one's given me a proper example of what they actually look like
from what I've heard there doesn't seem to be one on the IIGS board, but there could be one in the desktop bus keyboard, I just don't know what to look for

Looked through the pictures and others I found of IIgs motherboards and found no fuses.

However, I did notice a couple spots of concern on your motherboard.
1. Possible trace damage or incomplete connection from soldering.

2. Looks like one cut trace possibly two more damaged traces

 

[zanglucarson]

Looked through the pictures and others I found of IIgs motherboards and found no fuses.

However, I did notice a couple spots of concern on your motherboard.
1. Possible trace damage or incomplete connection from soldering.

2. Looks like one cut trace possibly two more damaged traces

View attachment 1798273

Oh my, I got so busy and completely abandoned this project! I checked the traces and everything seems fine, none those ones seem to be connected to the adb filter or the KBD MICRO chip.