15793 Views Previous 1 2 Next 21 Replies Latest reply: Jun 12, 2008 4:04 AM by flyjedi Go to original post
I may have located the problem for the loss of Bluetooth signal from the Mac mini to the wireless keyboard and mouse. My setup worked fine for about a year then I began having intermittent problems as many of you described. Having some radio background knowledge I first thought there may be interference from a strong RF environment.
One day I decided to take my mini apart as see what I could do. I found instructions on the web of how to do this. Viewing the inside there is a large metal plate which would be on the top side of the computer. There are two holes cut out of this plate at opposite corners and in the center of these holes, circuit boards with their own metal plates mounted to each circuit board. I do not have a circuit diagram for this computer but these two circuit boards look much like the radio frequency boards for the Bluetooth and WiFi. It appears that the small metal plates mounted on each board is the main radiating antenna. (On this point I could not be sure without a circuit diagram). The large metal plate appears to be the ground.
To connect the metal plate with the main chassis of the computer, a woven wire braid is used around the perimeter of the two cutout holes. This same type of braided wire is used on other parts of the chassis to obtain electrical contact. I assumed that moisture in the air has created poor contact between metal parts and the wire braid.
SOLUTION: For my computer I used white lithium grease and spread is on all the wire braid I could find. As the wire braid made contact with the metal parts, this grease improved the contact and will prevent or reduce corrosion on the wire braid.
After taking a chance and doing this, I noticed that loss of Bluetooth contact was dramatically reduced. There were a few times I lost Bluetooth contact but after slightly squeezing the computer in the vertical axis to ensure the metal to wire braid contacts were good, Bluetooth signal returned right away. Bluetooth is 99 percent functioning. I also read that Mac's Bluetooth radio range is not that far.
This type of electrical contact where it concerns radio frequency should be made by direct soldered wire connection.
I hope this can help as it has for me.
I was having bluetooth/wireless keyboard problems and changed a few settings based on suggestions found on this forum. Well the problem didn't go away. 2-3 days later the problem was gone and I could not explain why. After reading your post I remember that the weather was really bad i.e. wet and humid when the problem showed. I will see if the problem comes back when the weather gets rainy again...
thanks for the (possible) explaination
Not sure whether this has to do with the keyboard firmware update. I'm getting random disconnection from my wireless mouse and keyboard. It's not the broken Bluetooth icon thingy. My Mac mini Bluetooth seems to work properly. Just that out of a sudden, the keyboard and mouse decided not to work. I didn't get any lost connection warning. To reconnect, I have to power off and power on the mouse and keyboard. During power off, I get the lost connection warning. Weird. Maybe, it's an OS issue.
I don't remember the web site that showed how to open up the Mac Mini.
Also on this problem, after I used grease to coat the wire braids, my bluetooth connection with mouse and keyboard was not completely solved. It is about 95 percent solved. The very few times I have bluetooth connections problems, the mouse or keyboard reconnects. Then once in a while when reconnection does not occur, I found that if I grabbed the computer by the sides and gently squeezed it in the vertical axis, Bluetooth would reconnect.
The top and sides of the computer is one piece and the bottom the second piece. Both pieces are joined by plastic hooks. These hooks can be released by sliding a thin metal putty knife between the sides and bottom piece. Gently and slowly prying the sides away from the bottom piece. I'm assuming that there is some kind of electrical contact problem, so when I squeeze the computer as I described, this makes good the electrical connection that activates the Bluetooth.
The bluetooth signal also seems to be very weak. I have not yet opened up the computer again but will do so in the near future. I also intend to check on the Bluetooth antenna location to see what can be done about improving the signal strength.