Phone goes off hook automatically

[NEAXMAN]

Hi all,

I have a 34D in my kitchen that is extension 10. The phone goes off hook automatically. It seems as if the phone doesn't respond to the hook switch. It does this randomly, sometimes it works and sometimes it doesn't. Any advice would be appreciated.

 

[Kinneman]

Hi - I think your 34D phone has a defective mylar "flex circuit." When you press buttons on your phone, those buttons press on this flex circuit to complete the circuit for that pressed button. These flex circuits get internal shorts. When that happens, the phone acts just like yours is behaving. It is just like holding down a button - it disables all the other buttons including the switch hook. Your phone may also be making sounds like it does when a button is pressed - only rapidly and erratically.

You need to either replace this flex circuit (if you can find one) or replace the phone.

Regards,
Kinneman

 

[NEAXMAN]

Hi sorry for the delayed response. So is this mylar "flex circuit" the piece of rubber that goes in between the circuit board and the buttons?

 

[Dexman]

If you switch the phone with one that doesn't have the problem, does the trouble stay with the phone...or...the extension?

Also, try plugging the phone directly into the port on the processor to check inhouse cabling.

Lastly, program a one touch intercom button for x10 on another extension that has a free button with status LEDs and see if the system shows any unusual activity.

I "FEATURE 00"

http://dexman.webs.com/

 

[NEAXMAN]

Thanks for the response. I have tried changing the extensions and the problem stays with the phone. Cable is all brand new CAT5e and is fine. If you program a button to monitor it shows unusual flashing. For example, today the phone was auto-answering calls coming in on the CO lines. It is unplugged now. Guess I need a new one?

BTW-Recently got the phone as "Refurbished" Obviously it has problems.

 

[Dexman]

Yup, if the problem stays with the phone. Time for a replacement. Side question, is the phone an MLS, Euro I or Euro II? MLS phones were prone to membrane failures.

I "FEATURE 00"

http://dexman.webs.com/

 

[NEAXMAN]

It's an Euro Series I 34D. I bought the phone because of it's great physical condition. It's white without yellowing. Looks brand new. Too bad it's operation isn't as good as it's looks. Does anyone know where I could get the membrane or if I could replace it? If I could I would like to keep the phone "shell". Thanks.

 

[Kinneman]

NEAXMAN: When you first open the back of your phone, look at the circuit board. See two black edge connectors? There is a flex circuit that plugs into those black edge connectors. This same flex circuit wraps around to the other side of the circuit board (where the buttons are). This is called a "Flex Circuit" and it is the defective part in your phone. There is also a rubber "membrane" that goes between the actual buttons and the flex circuit. The rubber membrane does not cause this problem.

For what it's worth, I've tried cleaning the mylar flex circuits and I've searched them with a magnifying lens trying to find out what the problem is with no luck. There is a short somewhere in that circuit - but I've never found the problem in 4 of these that I've replaced - and cleaning it did not good either. Please do try to find out what is wrong with it if you can. If you are successful in repairing one of these flex circuits, please tell us what you found.

You said your phone was refurbished. I don't think this part would be replaced as part of refurbishing unless it was acting up during the time it was in for refurbish.

I looked at the sources I use for phone parts - and none of them have this part anymore.

For Partner Plus, Partner II, and Partner ACS Phone systems, I believe the most common phone is the "MLS-18D" or the "18D" - and many "wear" parts are available for them (including the flex circuits). I know for sure that the flex circuit is available now (February 2015) for the Partner MLS-18 and MLS-18d phones. If you have to replace your phone, consider going with one of those - for ease of service. With the MLS-18d phone, if you want wall mount, you just take the back cover off and flip it around, then re-attach it.

Here's some pictures of these flex circuits:
Link

 

[Dexman]

Ugh...flex circuit...not membrane.

Another option would be to pick up an 18D Euro II or two.

I "FEATURE 00"

http://dexman.webs.com/