Cisco 7940 hook switch problems

Hi,

We are suspecting that some of our Cisco 7940 and 7960 phones have
faulty hook switches (the switch underneath the handset).

The problems shows looks like the switch is 'sticky' or vibrating.

For the user, the problems seem like:
- Calls disconnect when answering then, and then user gets new dial
tone
- When dialing and picking up the handset, call go to wrong number
- It takes time for answering the call when picking up hanset (2-4
secs)

It seems like the problem shows up after about 3-4 months of usage.
New phones rarely have this problem, but after awhile it shows up
on all the phones.

Has anybody else noticed these types of problems???

-JJ

Jii

"Jii" <> wrote in message
news: om...
> Hi,
>
> We are suspecting that some of our Cisco 7940 and 7960 phones have
> faulty hook switches (the switch underneath the handset).
>
<snip>
> Has anybody else noticed these types of problems???
>
> -JJ

We've had the same problems with one of our 7960 handsets. I've also found
that you can disconnect a call by tapping around the hookswitch region with
the same handset or bumping the handset.

One day it disconnected an important call and I'd had enough.. I pushed on
the hookswitch hard with my finger - it hasn't done it since.

-Shaun

Shaun Ewing

On 1 Oct 2003 06:25:16 -0700, (Jii) wrote:

>Hi,
>
>We are suspecting that some of our Cisco 7940 and 7960 phones have
>faulty hook switches (the switch underneath the handset).
>
>The problems shows looks like the switch is 'sticky' or vibrating.
>
>For the user, the problems seem like:
>- Calls disconnect when answering then, and then user gets new dial
>tone
>- When dialing and picking up the handset, call go to wrong number
>- It takes time for answering the call when picking up hanset (2-4
>secs)
>
>It seems like the problem shows up after about 3-4 months of usage.
>New phones rarely have this problem, but after awhile it shows up
>on all the phones.
>
>Has anybody else noticed these types of problems???
>
>-JJ

I see this on phones mounted vertically. Cleaning the switch usually
works for a few months. The Cisco article says tap the switch
repeatedly as its supposed to be self cleaning.

-Chris

chris@nospam.com

Hi,

I think we are also seeing the same effect on some of the most used
buttons on the phones.

Some users complain that the 'Headset' button is behaving similary
erratic.
Meaning that pressing the key, seems to have 0.5 - 2 second delay
before anything happens.

-JJ

Jii

[insmmi]

This thread is real old but I wanted to add my 2 cents. If you open up the phone remove the tension wire and try to straiten it then use an eraser to clean the contact points (both the surface and the carbon tip that makes the connection) the phone will last a long time more. What I need is to find a place to purchase the actual contact point rubber piece and the surface with the cable. If I can buy those pieces then I can save a lot of money fixing the phone rather then replacing.

insmmi

[Bruno_vv]

Originally Posted by insmmi

This thread is real old but I wanted to add my 2 cents. If you open up the phone remove the tension wire and try to straiten it then use an eraser to clean the contact points (both the surface and the carbon tip that makes the connection) the phone will last a long time more. What I need is to find a place to purchase the actual contact point rubber piece and the surface with the cable. If I can buy those pieces then I can save a lot of money fixing the phone rather then replacing.

Hi, stupid question maybe, but how do you open the phone, without breaking it ? I'm having the same problem with 7960 phones, and would like to clean these switches.

Bruno_vv

[charles e]

The problems is not in the contacts getting dirty but is a function of the wear in the hookswitch lever pivots. The switch MAKES contact when you lift the handset. My Colleague Brent Densmore here at the University of Guelph found that if you put a screw in the lever hole or glue a plastic dot to the lever so that it puts more pressure on the carbon dot when the handset is up you will solve this problem that has plagued Cisco phones for five or so years.
& I think the chiefs at Cisco should give him a free weekend in San Francisco for resolving an issue that their own engineers and designers should have handled in the beginning

charles e

[RPaterson]

While Charles solution may work, how many people are going to feel safe and secure using superglue on their hookswitch? At IdacomUSA, hookswitch pads that are redesigned to work properly are sold for 15 dollars. Or for 85 dollars, we will completely repair and refurbish your existing and broken Cisco Phones.

Check us out at IdacomUSA.com

RPaterson

[IP Endpoints]

If you are in the UK - we also offer a repair service - ipendpoints.co.uk and click the repair service tab at the top.

IP Endpoints

[User52]

After removing the stand, unscrew all 4 screws, you can lift off the back of the phone using a flathead screwdriver. You can then clean the hook switch contact with any moist towlette that is handy after you remove it. I actually use the end of the wire spring to reinsert the contact back into the tiny holes. Works like a charm. These phones accumulate dust and gunk easily.

User52