How many beeps? The number of beeps it makes each time relates to a "beep code", which can tell you something about what's wrong.
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How many beeps? The number of beeps it makes each time relates to a "beep code", which can tell you something about what's wrong. Or is it making a solid tone, and not discernable individual beeps?
Have you tried resetting the PMU/SMC and the PRAM?
It's a longshot, but it could be that the power button is stuck, causing the power-on sequence to repeat continuously. To rule out that and the topcase/keyboard/power button assembly as the problem, I would disconnect the ribbon cable attaching it to the board, and then trip the power by bridging the power-on pads on the board. If the behavior is the same, you know it's not the topcase/keyboard that is the problem, and if it resolves the issue, you know the problem is somewhere in the topcase.
How many beeps? The number of beeps it makes each time relates to a "beep code", which can tell you something about what's wrong.
Have you tried resetting the PMU/SMC and the PRAM?
It's a longshot, but it could be that the power button is stuck, causing the power-on sequence to repeat continuously. To rule out that and the topcase/keyboard/power button assembly as the problem, I would disconnect the ribbon cable attaching it to the board, and then trip the power by bridging the power-on pads on the board. If the behavior is the same, you know it's not the topcase/keyboard that is the problem, and if it resolves the issue, you know the problem is somewhere in the topcase.