Receiver or TrackMan Dead?

Hi all, I have a Logitech Cordless Optical TrackMan that has suddenly stopped working. I have replaced batteries with several new sets to no avail. I have also tried plugging in the receiver on other USB ports and other computers and no luck. Any ideas? These have no lights of any kind so I can't tell whether the problem is at the device or the receiver.

Any help would be greatly appreciated.

Thanks.

Bill