CISCO 2960X Access Switch Issue Random Limited Connectivity Issue

[#1]

I have a CISCO 2960X Access switch which is configured in 3 Stack.

IOS Version 15.2(3r)E1 Software Image: c2960x-universalk9-mz.152-2.E5

The System is connected VIA the CISCO IP Phone and then terminated to the Switch (Including the Patch Panel).

But I am facing a lot of Limited connectivity Issue, as the IP Phone is Working Fine during this issue.

Cannot figure out the problem and its happening randomly on all systems and some times the issue is resolved automatically.

I have performed below step to rectify the issue with no results.

1. Checked the cable connectivity via the LAN Tester and it is OK.
2. Updated system LAN drives through dell update utility and is latest.
3. System replaced with a new system.
4. Replaced CISCO IP Phone ( as the system is connected VIA CISCO Phone).
5. Switch port configuration is similar to the other switches.
6. Windows OS 7 Professional 64 Bit.

I have another department in the same building which is using the 2960S Series of Access which does not face any issue.

Both The Offices are connected to the same DHCP & DNS Server.

[Leo Laohoo]

I have another department in the same building which is using the 2960S Series of Access which does not face any issue.

Don't be confused with the 2960S and the 2960X.  Both may come from the same 2K stable but the 2960S is far more stable than the 2960X.  As far as I'm concern, the 2960S and the 2960X are two fully different appliances.  

Have you tried connecting the clients direct (instead of connecting to the phone)?

[#3]

Hi Leo Laohoo,

quote: "Have you tried connecting the clients direct (instead of connecting to the phone)?"

Yes.Even, some users connected to a single 2960S and the 2960S connected to the stack, showed the same problem. Yesterday I disconnected the single 2960S and I connected it directly to my switch core. I hope it'll work fine. So far I think it might be the IOs (Version 15.2(3r)E1).