Obvious question: rent? If it's past due you can access your base but it will have no power or control.
Edit: if rent's paid and still no power, you'll need a GM to fix things up.
need more info
stupid questions to follow
when in the editor are the control/power bars full or empty
has a sg member been adding items to push power/control over
the person who said they paid the rent really paid
have you tried replacing your power/control units
ive had members in the past just randomily build stuff without telling me
then they panic when it breaks thinking ill scream at them
Thanks chaps. The answer was simply a rental issue, I'd clearly not paid as recently as I'd thought - although I haven't seen any notices to say my rental was due.
Anyhow, all solved so thanks for the replies.
I feel silly, oh so silly....
Thelonious Monk
No problem 
Sometimes the obvious answer is the first one we gloss over
I've noticed that very recently my base stopped working - in that none of my TPs, my Vault, my Work Benches etc ... and yet it was working and I've changed nothing.
Anyone shed any insight on this?
Thelonious Monk