I have bought a used nokia n900 phone from ebay which I have just received.
For some reason it could barely find the router which is 1 meter away from me. After some hours it could find all routers around. A few minutes later it could barely find the close router.
This happened a few times.
Now it can only find that same router but not all the others.
Is it possible I fix that somehow before contacting the seller to send it back?

I have the same phone and below it shows the differences.
Phone on top is the used I bought.
My previous phone is the second and finds around 10-12 routers

Thanks