New digibox for Multiroom, help!

I have recently had sky+ fitted and had my old box transferred upstairs for multiroom, everything was great.

I decided to change my box upstairs for an Amstrad DRX500 as it's a lot smaller and would look better. The problem I am having is that the box is sticks on standby as soon as I plug in the co-ox cable. When the cable is removed the box will turn on.

Any ideas???

[Cupart]

Have you checked that the cable is not shortening out the box? Remove the f-connector on the cable and make sure there are no "loose" metal threads from the outer mesh touching the centre hard lead...

Checked that mate, still no joy - The system still works okay with my old digibox, which leads me to thinking...

1: Either the new box is a duff (it was off eBay)

2:It needs installing and pairing up with the main sky+ box

I dunno....

[Cupart]

Have you tried to connect the box to the cable going to the SKY+ box, just to make sure it's not the LNB?