I know this is the PowerPC Macs forum. But since the keyboard came with my iMac G4 15", and the Mac Accessaries forum might not be a good fit for vintage hardware, so I posted here.
First, the family photo.
![1712765318963.png]( "1712765318963.png")
The iMac itself came in good shape. I got it from craiglist for less than 100 bucks. The seller also threw in a working iSight camera (firewire port) which you could see on the right rear side of the computer. The issue was that some of the keys on the keyboard didn't work, including the space bar which is critical for normal operations.
I did spend quite some time to clean up the keyboard. It was full of dirt and the keycaps were greasy. But that's definitely not the main problem. I thought culprits might be dust under the rubber domes. But even after thorough cleaning, all these keys were still as dead as stud.
After some research, I found a 9-year old Youtube video about repairing the same keyboard model. It was the turning point for me.
Following the tutorial, I did find two copper traces were broken with a multimeter. I also purchased conductive silver paste from a big online retailer. But when I tried to clean the green solder mask to reveal the underlining copper traces, I was stuck. In the video, the creator used a small flat head screw driver to peel off the solder mask. But it turned out to be a disaster for me. Perhaps the old traces became too frail, I ended up removing big chunk of whole traces.
![1712767264983.png]( "1712767264983.png")
I stopped after some damage and started digging. On some forums, people mentioned about using dry/wet abrasive papers to remove the mask. I immediately ordered some fine-grained (3000 grit) dry/wet sand papers from the same retailer and it was delivered the seond day.
I cut a small piece from the sand paper and dipped it in 99% rubbing alcohol, and carefully rubbed the green solder mask. In a few seconds, the mask started peeling off and the underlining copper trace remained largely intact! I quickly measured the conductivity between the revealed trace and adjacent joint and it had indeed continuity. Now it's time to apply the silver paste to connect the exposed trace with the broken joint nearby.
Because of the damage I had done previously, I ended using a far more paste than needed to do the repair. But eventually, all the keys are now working fine!
One thing I learned was that the conductive silver paste is NOT conductive when wet. And it takes time to settle. Once settled, it's as conductive as the old traces (by comparing resistence between joints with original trace and with repaired ones).
Now I have a fully working iMac G4 with the peripherals in great condiction. I did miss the original Harman Kardon speakers and just ordered a pair on eBay. Hopefully, I would have a full setup very soon.
First, the family photo.
The iMac itself came in good shape. I got it from craiglist for less than 100 bucks. The seller also threw in a working iSight camera (firewire port) which you could see on the right rear side of the computer. The issue was that some of the keys on the keyboard didn't work, including the space bar which is critical for normal operations.
I did spend quite some time to clean up the keyboard. It was full of dirt and the keycaps were greasy. But that's definitely not the main problem. I thought culprits might be dust under the rubber domes. But even after thorough cleaning, all these keys were still as dead as stud.
After some research, I found a 9-year old Youtube video about repairing the same keyboard model. It was the turning point for me.
Following the tutorial, I did find two copper traces were broken with a multimeter. I also purchased conductive silver paste from a big online retailer. But when I tried to clean the green solder mask to reveal the underlining copper traces, I was stuck. In the video, the creator used a small flat head screw driver to peel off the solder mask. But it turned out to be a disaster for me. Perhaps the old traces became too frail, I ended up removing big chunk of whole traces.
I stopped after some damage and started digging. On some forums, people mentioned about using dry/wet abrasive papers to remove the mask. I immediately ordered some fine-grained (3000 grit) dry/wet sand papers from the same retailer and it was delivered the seond day.
I cut a small piece from the sand paper and dipped it in 99% rubbing alcohol, and carefully rubbed the green solder mask. In a few seconds, the mask started peeling off and the underlining copper trace remained largely intact! I quickly measured the conductivity between the revealed trace and adjacent joint and it had indeed continuity. Now it's time to apply the silver paste to connect the exposed trace with the broken joint nearby.
Because of the damage I had done previously, I ended using a far more paste than needed to do the repair. But eventually, all the keys are now working fine!
One thing I learned was that the conductive silver paste is NOT conductive when wet. And it takes time to settle. Once settled, it's as conductive as the old traces (by comparing resistence between joints with original trace and with repaired ones).
Now I have a fully working iMac G4 with the peripherals in great condiction. I did miss the original Harman Kardon speakers and just ordered a pair on eBay. Hopefully, I would have a full setup very soon.
