We acquired in 2016, 220 cisco Phones 7821, currently more than 20 ipphones are down, they all have the same probléme which is 'network unavailable' , the pin (RJ45) are not damaged, we have changed the cable, used other switch, reset phone, phones still not working.
I read in the forum that it's a Hardware design error (ETH socket mounting), please help us to find a solution, so that this problem does not reach more phones.
regds,
