I have dealt with this situation many times and I can say there has been no resolution other then a replacement of the device.
The 5 vibrates is a Qualcomm download mode and I have not figured out how to get out of it nor how one finds themselves in it in the first place.
Like the user, you can flash the RUU or PB31's all you want and it might fix the issue to the point where you can boot it with the USB plugged in but the device will never be the same again.
In my attempts to figure it out I have rebuilt internal partitions, Flashed radios, Hboots, full OS's, MFG Hboots, and unicorns. All have led to the same result.
Just thought I would put out my .02 as I have seen this issue many times.