Author Topic: Strange phone problem - can anyone help? (Read 8444 times)

Carol Haynes · « **on:** May 23, 2011, 12:48 PM »

I had to replace my cordless phones and after looking at lots of different makes opted for Panasonic as they had good reviews and most other makes didn't seem to fair so well.

I have a main socket and a single extension with a wired phone on the extension and the cordless base unit on the main socket. Both had ADSL filters.

I have absolutely no problems making calls from the wired phone, and my previous cordless phones worked fine (albeit with really crappy sound).

The Panasonic phones have a problem - any number that has a 3 in it (or if you are using 3 to navigate menus) don't work - at least not consistently.

Given that the area I live in has a 3 in just about every number it takes about 3 or 4 attempts to make a call (using redial - so the number is correct). I just get number not recognised more than 50% of the time and if I am using menu navigation on a switchboard it just doesn't seem to hear 3 when pressed.

I returned the phones as faulty to Amazon and got a replacement but exactly the same problem. I have nmow changed model number (still Panasonic) and still get the same issue.

I have tried turning off broadband in case there was a frequency clash but that doesn't seem to make a difference.

One of the reasons I liked these phones is that they support call chaining from the address book. I make a fair number of overseas calls and use access numbers so call chaining is really handy - unfortunately it is almost impossible to dial my mother's number without error - even manually!

Has anyone got any clue how to troubleshoot this and work out how to fix it (other than just sending them back and getting a different make).

nudone · « **Reply #1 on:** May 23, 2011, 01:25 PM »

It might be something weird like you are assuming but until you try the phones at someone else's location I don't think you'll really know what to blame. I mean, what if it's a design fault with the 3 button? I suppose you could test a phone from Argos, see if that works then take it back - if they allow it on phones.

Ath · « **Reply #2 on:** May 23, 2011, 01:25 PM »

Assuming it's a Dect phone, isn't anything else in the 2.4 GHz band disturbing the signal to that phone? like a wifi router from your ADSL connection, or something like that.
Even if the frequencies are (a bit) different, a strong signal transmitted from close proximity can overwhelm a receiver so much that it can't correctly receive or separate the normal equipment it's designed for. And that would explain why the replacement set has exactly the same issue. That the interference is only when dialing 3's is just an unlucky coincidence, I guess.
Putting either aside for several feet should significantly improve the behavior. (that is assuming you have a wifi router or other transmitting equipment, like a CRT-TV nearby)

Carol Haynes · « **Reply #3 on:** May 23, 2011, 02:39 PM »

Yes it is DECT The base unit sits next to the router - but the problem persists when the router is unplugged!

Nudone - you are correct I need to take it to a neighbours house and try it there to eliminate something in the house.

The strange thing is I had a set of BT Calypso DECT phones before and never had any issues at all.

Stoic Joker · « **Reply #4 on:** May 23, 2011, 03:17 PM »

Defective 3 is way too specific for an interference issue.

The wired phone working eliminates a line issue.

Signal bleed would cause calls to drop, low call volume, or line noise. I'm with Nudone on the you need a tie-breaker type diagnostic. But it sounds like a bad batch of phones.

Carol Haynes · « **Reply #5 on:** May 23, 2011, 05:59 PM »

That's what Amazon said - but then I ordered a different model - so now I am on to my third set of phones and two different models and they all have the same issue (which wasn't there on previous Dect phones).

There doesn't seem to be any logic unless there is something specific in Panasonic phones that is different to other Dect phone?

Stoic Joker · « **Reply #6 on:** May 23, 2011, 06:27 PM »

Maybe a silly question, but when you push the 3, can you hear the tone on the line? Does it sound any different/odd?

Shades · « **Reply #7 on:** May 23, 2011, 06:43 PM »

You use to have a 'pulse/tone'-switch on telephones/base-stations. Don't know if DECT phones still have those as I didn't use a landline for years now. But if it has one, you could try to set the switch in a different position.

My father used his telephone with rotating disc (pulse) on the Dutch phone grid till he passed away last year. Most neighborhood switch stations still accept those pulse phones and convert their signal to tone.

Given this I think it is highly likely that your neighborhood switch is also still accepting those signals. If there is still such a switch it never hurts to try.

Carol Haynes · « **Reply #8 on:** May 23, 2011, 07:06 PM »

Yes I can hear the tone - and it works probably 25% of the time on average.

Yes my exchange can use pulse as well as tone but it works fine from the wired phone on tone and also worked fine on my old Dect phones on tone. It's academic anyway as the base unit doesn't have a pulse switch.

40hz · « **Reply #9 on:** May 23, 2011, 07:20 PM »

Do you have a monitored home alarm service on the same line? Likely not since they usually won't share a line with ADSL traffic, but you never know. If there is an alarm monitor on the same line, they might be suppressing the DTMF for number 3 because it's being used by them for something. Same goes for a VoIP router if you have one of those. There are cases where "jitter" buffering can prevent some tones from reliably getting through. Ask your ISP/voice carrier if there's a problem with compatibility for Panasonic phones. Or just that nasty git of a number: 3.

If you experience the same problem after swapping back your old phone, then it's definitely something up with the telco or ISP. I'd guess it was a recent change on their end that's causing it.

Long shot: does Panasonic have a UK specific version, or setting, for this phone? I don't know if the UK still goes it's own way as much as she used to. But there may be something the rest of the world is now doing (that the UK isn't) which is making this particular phone incompatible. Possibly the British DTMF for 3 is different than Panasonic's current one?

mouser · « **Reply #10 on:** May 23, 2011, 08:13 PM »

those panasonic phones are quite nice.

i would suggest you do the same thing i would suggest with any mystery hardware problem. go buy yourself a cheap non-electronic non-wireless no-frills corded telephone, and verify that the 3 always works with it. if not, then you know the problem has nothing to do with your panasonic. and you can keep the non-powered phone as backup in case you ever lose power.

Carol Haynes · « **Reply #11 on:** May 24, 2011, 04:19 AM »

Problem solved (sort of).

I replaced the cable - which makes things a lot better but not perfect. I should have thought of this before - the socket is in a really difficult place to get at so the only common feature of all 3 phone sets was the cable. It still isn't 100% but it is more like 90% working now.

Additionally I have now moved the base unit to the kitchen and it seems to work fine. The kitchen is an extension off the main socket (where it was plugged into so why it works in the kitchen I can't imagine!

Anyway thanks for the suggestions.

cranioscopical · « **Reply #12 on:** May 24, 2011, 07:52 AM »

Glad you found a way out of that one!

the socket is in a really difficult place to get at…
so why it works in the kitchen I can't imagine!

-Carol Haynes (May 24, 2011, 04:19 AM)

I think you have all the information to work out the reason. There wasn't mushroom in the original location!

40hz · « **Reply #13 on:** May 24, 2011, 11:22 AM »

Additionally I have now moved the base unit to the kitchen and it seems to work fine. The kitchen is an extension off the main socket (where it was plugged into so why it works in the kitchen I can't imagine!

Probably wanted to be put there so it could more easily sneak teaspoons of jam when nobody's looking.

Stoic Joker · « **Reply #14 on:** May 24, 2011, 12:24 PM »

I replaced the cable - which makes things a lot better but not perfect. I should have thought of this before - the socket is in a really difficult place to get at so the only common feature of all 3 phone sets was the cable. It still isn't 100% but it is more like 90% working now.
-Carol Haynes (May 24, 2011, 04:19 AM)

It seems there's a lesson in this for all of us. As none of us suggested anything that basic, because we all collectively assumed you'd already tried it. - oops! - I guess it really doesn't hurt to ask...

Glad you got it working.

Carol Haynes · « **Reply #15 on:** May 24, 2011, 01:03 PM »

Its OK - I hang my head in shame at missing something so stupid.

Still like to know why changing sockets mad the final difference?

40hz · « **Reply #16 on:** May 24, 2011, 03:21 PM »

Still like to know why changing sockets mad the final difference?
-Carol Haynes (May 24, 2011, 01:03 PM)

After eliminating the cable:

Semi-shorted outlet
RF Interference along the wire run leading to the bad socket
Damaged insulation in wire run leading to the bad socket
Bad connection to demarcation point for that socket
Dirty outlet contacts
Loose outlet contacts
"Just one of those things"

It's endless. If replacing the outlet doesn't cure the problem it's likely something in the wire run. Often it's something that didn't used to be a problem until the newer generation device couldn't get its required level of line quality. There's also a good chance something just recently happened to that wire which merely coincided with your needing a new phone. Hard to positively determine a cause without some fairly expensive test equipment however. And hardly worth it if you don't need to use that length of wire.

FWIW, I had a similar experience with phones in a new client's office. Everything worked perfectly except for one outlet located about 50 feet from the phone closet. We replaced the outlet, but to no avail. A quick check on the line showed it had a marginally higher electrical resistance than it should have. But nothing that looked to me (admittedly an amateur when it comes to phones) too far out of the ordinary.

The "phone guy" we brought in however, said: AHA!

He plugged a line analyzer into the circuit and got a report back that the wire run length was about 400 plus feet. We looked up in the ceiling and found a knotted ball of phone wire about the size of a soccer ball jammed between the wall and a half dozen electrical lines powering the fluorescent ceiling lights. All we could guess was that whoever installed that line had somehow managed to knot up their roll of cable in the middle when they were pulling that run. Only afterwards did this person realize the clean lengths of wire wouldn't stretch to reach both ends of the circuit. So rather than run a whole new line, he just punched down both ends, left about 325 feet of kinked mess in the middle, tucked it out of sight, and called it done.

Once that copper "beachball" got removed, the jack now worked properly. And entire Trixbox phone system started working much better than it had previously. Apparently that mess was acting like a coil and causing all sorts of intermittent noise problems for the phone server.

Our client just assumed that their occasional phone problems were a trade-off they had to live with since they were using the "community edition" of a FOSS-based product. $:-\$

mouser · « **Reply #17 on:** May 24, 2011, 03:46 PM »

ha! great story 40hz.

40hz · « **Reply #18 on:** May 24, 2011, 05:52 PM »

^We took pictures of it. If I can remember where we saved them I'll post them.

Carol Haynes · « **Reply #19 on:** May 24, 2011, 08:52 PM »

Thanks for the all the ideas and a great story.

The really strange part is that the socket where it had a problem is the master socket and now it is connected to an extension (off an adapter) and it works. I have moved the wired phone to the master socket and that seems to work without issue too.

All very peculiar - but you are probably right - it is likely to do with QoS.