7942 Phones - call disconnect issue

[Yort Mantup]

Hello,

Experiencing a strange intermittent issue with a site and their 7942 phones.  The issue just began last week and the phones have been in place for 6 months.  When hangin up the handset, the call will not disconnect, the user has to press the end call soft key.  this occurs on outbound, inbound or calls to voicemail.  I have asked if there are ever issues with when making outbound calls using the handset, if there is trouble getting dial tone.  The answer was no.  My first thought was we're dealing with a batch of phone with bad switch hooks but that does not seem to be the case.  I am unable to think of any other cause. Any idea's???  Thank You

Phone Firmware Used is:  SCCP42.9-1-1SR1S

Voice service is Verizon SIP

Call Manager 8.5

[acampbell]

Hi,

Cisco are aware of issues like this.

Usually it is the physical switch hooks on the phones are sticky

Look at this link.

http://www.cisco.com/en/US/products/hw/phones/ps379/products_tech_note09186a00801c0810.shtml

Self Cleaning Hookswitch Contacts

The hookswitch contacts design uses a wipe action to self-clean the contacts. Periods of nonuse of the phone allow air impurities such as dust and other contaminants to hinder contact performance, which results in intermittent operation. Press and release the hookswitch rapidly a dozen times or so to clean the contacts.

Try giving a test phone a clean.

Regards

Alex

[Andrew Skelly]

You might also want to look at the cradle as well.  Just below the hookswitch and just above the speaker is a small tab that you can remove and insert one of two ones.  One way will let you hang up the phone normally.  The other way offers a small protrusion that allows you to securely hang up the handset.  If the phones have the small tab displaying, it can make it appear that the phone is onhook, when in reality it is sitting on the tab and not the hookswitch.

In the image below, #1 is without the tab displaying and #3 is with the tab displaying.  To swap out the tab, simply push down on the hookswitch and slide the tab up.

[Rob Huffman]

Hi Troy,

I'm going with you, Alex and Andrew that this sounds like a Hookswitch problem (+5 guys )

But I think it's probably related to the 9.1.1 Firmware. Here are 3 related bugs;

CSCti17718 - No dialtone while setup a new call with handset offhook

CSCti13009 - Phone can't answer the call by offhook or press headset/spea

CSCti49760 - Incoming call cannot be answered the first time by offhook

I would try upgrading the firmware on one of the trouble phones to see if it fixes the issue.

Cheers!

Rob

[Yort Mantup]

Typically a bad hookswitch is more consistent once it first happens in my experiences - Rob - the bugs related to the firmware does seem a more likely cause but I don't see where these three describe the issue that is occuring:  call does not hang up when handset is hung up, or am I not understanding the bugs correctly? 

Thanks!

[Rob Huffman · Accepted solution]

Hi Troy,

You're right We've changed out a fair number of IP phones due to the Hookswitch

issue and once they're cooked they're cooked

I think my reference is that these 3 bugs indicate to me a common thread related

to the Hookswitch. They are not exact to be sure, but I think the problem you are

seeing might manifest from the same underlying firmware issues.

Cheers!

Rob

[Yort Mantup]

Got it!  I'll take your suggestion on upgrading the firmware on one of the phones and go from there.  Thanks again everyone!

[moataz_mamdouh]

Look at this

CSCto78441