[cisco-voip] Hookswitch problems on IP phones

[Mike Armstrong]

I appreciate the information from everyone.  I was naively comparing the 
$315 7940 to the Western Electric 500-style phone and expecting similar 
mechanical reliability.  I can just see the expression on my boss's face 
when I tell him to "Press and release the hookswitch rapidly a dozen times 
or so to clean the contacts."

So far, TAC has RMAed all my mechanical failures under my Smartnet contract, 
but I've had to argue with them once, and I'm concerned about the increasing 
failure rate.  If we're expected to repair them ourselves, it would be a 
nice gesture on Cisco's part to make spare parts available.

mike

> Date: Wed, 31 Aug 2005 16:28:20 -0400
> From: "Lelio Fulgenzi" <lelio at uoguelph.ca>
> Subject: Re: [cisco-voip] Hookswitch problems on IP phones
> To: <cisco-voip at puck.nether.net>
> Message-ID: <007a01c5ae6a$873f34c0$30196883 at cfs.uoguelph.ca>
> Content-Type: text/plain; charset="iso-8859-1"
>
>
> http://www.cisco.com/warp/public/788/AVVID/hook_switch.html
>
> in short,
> Introduction
> A thorough analysis of a large number of Cisco IP Phones that have been 
> reported as hardware failures has been completed and our research reveals 
> that the great majority of these phones do not have any determinable 
> failure. The standard by which the phone industry measures phone failures 
> is based on Bell Corp/Telcordia standards and the standard acceptable 
> failure rate is set at 4 percent. The Cisco IP Phone's overall failure 
> rate is well under the acceptable industry average. Many of the problems 
> that have been reported as hardware failures are really either operational 
> or cleanup issues. This document describes some common troubleshoot steps 
> to be taken before you attempt to replace the Cisco IP Phone.
>
> 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.
>
> If none of the solutions above remedy the situation, Return Material 
> Authorization (RMA) the phone.
>
>
> --------------------------------------------------------------------------------
> Lelio Fulgenzi, B.A.
> Network Analyst (CCS) * University of Guelph * Guelph, Ontario N1G 2W1
> (519) 824-4120 x56354 (519) 767-1060 FAX (JNHN)
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> "I had a coffee and Coke at lunch today...and now, I've got more jitter 
> than an
> IP phone on a long haul 10base2 connection" 
> LFJ
>  ----- Original Message ----- 
>  From: Mike Armstrong
>  To: cisco-voip at puck.nether.net
>  Sent: Wednesday, August 31, 2005 4:25 PM
>  Subject: [cisco-voip] Hookswitch problems on IP phones
>
>
>  We're starting to see problems with the hookswitches on 7910 and 7940
>  phones.  First occurrence was a couple of weeks ago, now 2 more in the 
> last
>  week.  Is this a trend, I wonder?  (Phones are about 5 years old.) 
> Symptoms
>  are that when the phone is lifted off-hook, the switch only goes off-hook
>  for a brief instant, then goes back on-hook.  The caller only hears a 
> brief
>  click followed by a dead line, and the callee gets a bum rap for hanging 
> up
>  on his callers.  One of my guys suspects the spring in there is 
> weakening.
>  Is anyone else seeing similar problems?
>
>  Mike Armstrong
>  UF/IFAS CREC
>  Lake Alfred, FL