In our experience, 'shorts' on most telephone lines are caused by some wiring issue.  Below are some tips on how to resolve this issue:

- Carefully inspect the cooper wires inside the 2 sockets of your call blocker (LINE & PHONE).  If you notice any bent wires, this could be cause a short.  If possible, try to line up these wires with a small plier or similar tool.  If you are unable to fix these wires, please contact us to request a replacement (free if within first 30 days of purchase).    

- If cooper wires look okay, you should try using a different 2-way splitter (if you are using it for a parallel setup).   You may also try to switch the patch cords, phone jacks, modem port, or any other device that may be causing the short.  Your goal is to be able to identify the source causing this 'short' issue and fix it.

If you were able to isolate this 'short' issue to the call blocker, and you inspected the inside wires in both RJ11 sockets (LINE & PHONE) and still have this issue, please contact us to request a free replacement (if within 30 days).