Powertap Problem, CPU, Hub, or Receiver?

Originally Posted by GIH

Hey ya'll I have a powertap problem.

When I turn on the computer no transmission icon is displayed. No power is displayed, nor are any of the other quantities that the powertap can measure with the exception of speed.

Whether or not the wheel is turning the CPU displays a non-zero velocity, which rapidly fluctuates (from 5mph to 90mph).

I took the CPU out of the receiver cradle and performed the loop communication test (test 8 in the instruction manual). However, when I shorted the gold leads with a coin the hub was reset and I no result was registered for the test. Upon further examination shorting the leads also caused the CPU to display a random nonzero velocity for a small period of time. This leads me to believe that the CPU is the source of the problem.

Just in case I'll mention the circumstances under which the problem developed. I have had the powertap for 2 months. When I first installed it I accidentally cut the receiver wire while trying to trim one of the zip ties. I was able to reconnect the different strands with electrical tape, and the powertap started working again. I had to retape these strands one time in the past two months when the tape slipped off the wires. I have since purchased a new harness but I have not yet installed it. I did place the receiver next to the hub and test to see if the new receiver solved the problem, but it did not.

The problem started about 10 days ago while I was riding inside on a trainer. The previous day though I was riding back home from a race when it started raining extremely hard outside, but the problem only occurred after about 30 minutes on the trainer the next day. I tried opening the hub to dry it out but there was no improvement after 24 hours.

So do you guys think that my problem is the CPU? I assume that these are covered under warranty by cycleops, and I might be able to borrow one from a powertap dealer if I am lucky. Is there anything I might be able to do to fix my CPU? I don't see any way for me to repair it, but I might be wrong. Perhaps it needs to be dried somehow?

Or is there an additional problem, and if so can I fix it myself? I have about 100 hours on my powertap batteries, could they be dead by now? Might the antennae be damaged?

I appreciate any help you guys can offer. By the way, it stopped working shortly after I set a PB for 5 minute power which I was really excited about. Thanks.