Mine didn't work when I first got it. I opened it up to clean the RF/VF and the frame select mechanism. I GENTLY moved the needle with my little screwdriver and it came back to life! The 7 I have I expect was stored for years with no activity and the needle simply had frozen in place.
Also, IMHO there is alot of opnions about selenium meters. Mine is as accurate as it needs to be for most 400 speed film....taking in account exposure errors. Most of us compare these to our ultra sensitive digital camera meters and proclaim these selenium meters as "unreliable and innacurate" Keep it in perspective. Also, you probably know this already, but there is a zero adjustment screw available just under the top cover to bring the meter to the black zero mark if it is off. I also have been able to coax the meter into working on another 7 simply by adjusting this screw.
I love my 7...Hope this helps and happy shooting!