Got a fun one here.
a simple Partner Plus 3.1 CPU, nothing fancy.
Ext 13's keypad started to fail for buttons 3,6 & 9.
Resetting the phone fixes problem for a few hours, then trouble returns.
Swapped phones (and line cords)- problem followed.
Swapped ports @ KSU - Problem followed.
Installed new telephone and cord - problem continues.
Double checked connection and RJ45 at KSU / MDF - all looks good.
Cannot see any corrosion or twisted cabling.
The only constant in this problem is the actual cabling, which I've never heard of causing this type of problem.
Cannot change pairs on cable due to another ext already using those pairs.
(That ext is working fine w/o issues.)
My next step is to locate some chicken bones to remove the evil spirits.
Anyone had this trouble before on a Partner Plus?

Thanks
Gonzo

Just to rule out the cable run a two pair wire from the D-marc to the phone, see if this fixes the problem. We've had mice chew on a wire and only bite 1 pair and caused some strange problems.

No, no way could this be a wiring problem. Simple way to check is to plug a phone directly into the 206 extension port.

What do you mean by "trouble followed"? Do you mean that when you swap phones the trouble stays with the phone or the extension?

-Hal

Is this a mls[12][12d] phone per chance ??

Seriously? You swapped the phone, line cord and KSU and the problem persists? That's not possible.

The fact that the trouble follows 3, 6 and 9 suggests either a problem with the set membrane (the digits are in the same column) or some bizarre touchtone detector problem with 1477 Hz. Which begs the question: Are you also having a problem with the "#" key?

Of course, the business of so-called unlucky x13 and chicken bones may need some reconsideration.

Try moving 13 to another port

thanks for the replys.

Yes it it a MLS 12D telephone.
and yes the trouble follows even with a different known-good telephone - also MLS 12 btn.

Have already changed ports back at the KSU, ( swapped 10 & 13) cant do alot of port swapping due to office activity.

To be honest, Im just hoping this customer replaces this system

Really no reason to replace the system just because you can't figure out this problem. I have plenty of Partner Plus and MLSs out there. At most I would recommend an upgrade to an ACS and replace any defective expansion mods.

Sounds to me like you need to get in there after hours with some replacement mods and start troubleshooting.

-Hal

I would immediately suspect bad keypad membranes in both phones, but that is my bias as an equipment repair person.
Have you taken the -12D to another heavily used location to see if the trouble occurs there? If it does, you have a bad membrane. The failure of the 3-6-9 button column tends to point to this.