During rainy weather a friend accidentally dropped his BlackBerry into a puddle. After that, the trackball stopped functioning properly. So I took it apart.
Remove the back cover of the blackberry. Extract the battery, sim card, and micro sd card.
Pry the clip on the back of the phone with a plastic screwdriver. Also remove the T6 Screws, there are 4 visible, and 2 which are hidden underneath that clip. One of the visible screws may be hidden underneath a no entry symbol sticker.
Next pry the backplate off the phone with the plastic screwdriver.
Next, move the printed circuit board (pcb) out of the way. Remove the three ribbon cables. The white antenna cable can be left alone.
Here’s a video to help you guys out in taking apart the BlackBerry 8900.
On the reverse side of the blackberry on the trackball PCB, I noticed some corrosion on the bottom right corner. I cleaned it with rubbing alcohol. Allowing the trackball to scroll properly in all directions.
Corrosion on the bottom left corner contains dissolved salts from the water which are conductive preventing the trackball from working properly.
However even though the trackball was scrolling, it was not clicking properly. I thought that its possible there was some corrosion or damaged electronics that went unnoticed so I ordered a new trackball on ebay. To remove the old one you have to pry out the metal plate where the trackball PCB sits. Be careful not to break surrounding components.
Here you can see I bent an edge connector that goes to the LCD by prying open the metal plate for the trackball PCB and using the edge connector as the fulcrum for the lever/screwdriver.
Luckily I didn’t bend that one too much, so I just bent it back as much as I could and it was fine. However with the new trackball from Ebay it would not scroll in all directions or click properly. I had a feeling it was not getting a proper ground connection as the new trackball did not have the foil sponge stuck on it as the old one did. When you put the PCB back, the sponge is supposed to make a proper ground connection.
The Part where the metal sponge connects to the ground plane on the PCB.
I tried everything including a ball of foil, that’s when I figured its probably cheap china made junk. Compare the two PCBs.
The original trackball is on the left and the trackball from ebay is on the right. Looks poorly made and drenched in flux.
That’s when I was like, well at least the original trackball could scroll in all directions the ebay one couldn’t even do that, so then I decided to check one more thing on the original trackball, and that was the conductivity of the tactile button. My battery was dead on my multimeter, so I decided to do a manual look at the button by taking the button apart. There is a small piece of tape over the button. That tape is yellow in color and I believe is heat resistant. This tape is used to protect heat sensitive components during solder reflow processes.
Taking apart trackball tactile button I noticed corrosion under the metal dome and on the contacts below it.
After cleaning it up, you'll probably notice a big difference. After putting it all back together the original old trackball worked perfectly fine.
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