I have not been able to sync my device, it keeps connecting and disconnecting by itself. I’ve tried with four different pcs and a MAC.
I have encountered this when trying to connect a Clip via a non-powered USB hub. Some Sansa players will connect without problem through a passive USB hub, but in my experience the Clip absolutely NEEDS a powered hub. When connected via a passive hub, it behaves exactly as you describe.
If you are NOT connecting via a passive hub, then a variety of possible failure modes spring to mind:
Powered hub that is defective (i.e., not providing power, or, providing insufficient power)
Defective cable (one or both of the power wires broken, or disconnected from the connector internally)
Dirt of some sort on on one of the connectors (either end of the USB cable, or, the Clip’s connector)
Defective Clip (if you are still experiencing the problem when using a DIFFERENT cable, on more than one computer, and you have inspected the Clip’s USB socket and verified that there is no gunk inside, then it’s RMA time, IMO)
[[Note to Sandisk admins – I get an error – “Your post has been changed because invalid HTML was found in the message body. The invalid HTML has been removed. Please review the message and submit the message when you are satisfied.” – when applying italics (via the “I” button in the message editor) – I am now using UPPERCASE in place of italics, but that is a less-than-ideal workaround for the editor bug.]]
I had the same problem. It turns out it was caused by using a USB cable that was not right. I lost the one the came with the Sansa Clip. I found another one that “fit” the port on the Clip. Whne plugged into the powered USB port, it would say “writing” and would connect and disconnect from the PC. I tried another cable and it would charge the Sansa Clip but did nothing else. I notice that the end of the cable that connected to the Clip, although it fit the port, looked to be set up a little different on the inside. I then tried another cable (this one came from my portable, external disk drive) and it worked fine - Clip connected to the PC, the PC recognized it, and everything transfered fine. Bottomline is to make sure you are using the right cable. Just because it will “fit” into the port on the Clip does not mean it will work.
Some cables are power only (no data)–personally, I dislike them and find them confusing (although some may like them as a way to charge via a computer’s USB while still playing the player).