[Nexus 7 Q&A, Help & Troubleshooting] bftb0:
Hi dejan16v

Happy holidays!

I am frankly surprised at how poor *both* those devices are**, but it is apparent that your N7 is about 20 dBm worse on average compared to the N4 (it observes a signal 100x weaker than the N4 on average).

I have an old Linksys WEP router, and I made several measurements using that older router. At one meter distance (Ch 3), the best signal I observed on my N7 was -37 dBm. Note how different this is compared to my current WiFi router (best case of approximately -15 dBm). Both of those routers (Linksys) have two external antennas which may be positioned at any angle desired.

I fooled with my old router - the firmware has "diversity tuning" options - and also I ran it removing one and/or both antennas. (Not really a good idea, but it is an old router that I almost never use, so I don't care if it gets destroyed). What I found out was that one of the two antennas was very weak compared to the other ( 20 dBm worse), so perhaps the reason my N7 sees -14 dBm on my new router and -37 dBm on the old one is that the hardware is damaged on that older one. That older router is flaky enough that sometimes the radio doesn't even come on when I power it up.... but even in that case on my N7 I see a signal nearly 100x better than what you observe on your N7 ... and on my newer router, nearly 10,000 times stronger.

So I think you do have a little problem.

The N7 has its external antenna attached to the back case, and it makes electrical contact to the motherboard with two small, slightly spring-loaded, contacts that rise up off the motherboard. It is possible that you simply have an issue where the back cover is not tight enough to make a good connection to the antenna.

Have a look at this XDA N7 thread, it includes a picture of these antenna contacts located near the battery connector. (One of them has broken off!)

or

(from thisXDA post.)

Several people experiencing low WiFi signal on the N7 simply had problems with the back cover of the N7 making good contact, and they tried a couple different hacks to improve the contact. But beware - several people also reported accidentally breaking the contacts when they fooled with them!

If this makes you uncomfortable, perhaps you could return your under-warranty tablet. The only thing that I see that is possibly wrong with a RMA strategy on a 2012 N7 is that (maybe?) they are not being made any longer, and you will only get a refurbished unit instead of a new one as a replacement.

good luck; this is my last post in this thread. My assessment is that you do have a problem - which might be corrected by something as simple as popping off the back cover and then re-installing it. But, it could be any number of other things as well.

cheers

** making WiFi signal strength measurements is not particularly easy. I have an old Android phone which reports very similar signal strengths as my N7 - but only at long distances from the router. Very close to the router - where the N7 can see signals as powerful as -15 dBm, the phone is much much worse ( ~ -35 dBm). In addition, my N7 (using my router) shows very strong polarization effects when it is close to the router (the signal goes from -14 dBm to -35 dBm just by rotating it by 90 degrees). When I am at some distance from the router, however, that polarization sensitivity disappears. The "weak" phone shows no such polarization sensitivity either close to, or far away from the router)

Some of this is no doubt a strong function of the radiation pattern produced by my specific router, plus all the radio clutter in the nearby environment (walls, metal objects, etc).