Why is my camera not recognising the camera lens?

Googling indicates many people are having this problem. The only affordable answer I've found - but not tried yet - is a paper shim, discussed on a DP Review forum.

"Hi guys!

I know this is an old thread but maybe there are still Nex users with this problem, so i hope this will help you. Don’t pay much money for repairs or throw away your Nex, that’s not necessary!!!!!

”My” solution is from a german DSLR and DSLM forum. The contacts are not dirty, they are CORRODED!!! I have/had the same problem and brought my cam to a Sony partner. Diagnose was a broken power line on the board. Repair = about 250-350€ —> never ever!!!!! I bought last year a used A6000 for 400€, so i’m not crazy to pay for the repair of an old Nex-5 about 300€. Anyway…. i browsed throug the internet and found people had the same problem and one guy (a technician) told that he solved the problem with a simple contact spray for about 5€. ;-) So i gave this a chance… bought such a spray and “cleaned” with it carefully the contacts (on both…. the cam and the lenses). Then i gave away the cam for a few days to let the contact solution work. And guess what….. after these few days the cam worked as fine as a new cam. :o)

But the problem is, this “defect” is WANTED by Sony!!!!! It’s “planned obsolescence”. So the problem is solved only temporary. That means for a few years. ;-) Then the contacts corrode again. I bought my Nex-5 in 2010 i think. First time i had this problem was a few months after warranty was over. :-( Perfect timing from Sony. But i could “repair” it as i discribed. Now we have April 2019. I had the problem a few weeks ago again…. took out my contact spray….. everythings fine again for the next few years.

I hope it helps you!!!!

Fritz"