Author Topic: Merlin Single Line Set  (Read 5267 times)

Alex G. Bell

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Re: Merlin Single Line Set
« Reply #15 on: July 15, 2017, 09:26:23 PM »
Sorry for the long reply.

I purchased 2 on eBay to see if they'd work as an straight analog phone. The jack in the back of the phone is a standard-look 4 wire modular (standard phone line cable width, not handset nor 8 conductor larger connector).

Plugging it into my Panasonic system with a 2-wire lead results in the following: off-hook, no dial tone, nor does it break the circuit; on-hook, the phone rings (also when the handset is off-hook does it ring).

... I'll try and trace the circuit to see if the outer pair go somewhere on the circuit board - for giggles I may connect to one of the row 1 ports on the Panasonic to see if the 5 volts provided gets this thing going...
The 7101 (like the 7102) is an analog phone that works on any analog line and if in working order will work on an analog station jack of a Panasonic system.  What Panasonic system are you using?

"breaks the circuit"?  What do you mean?

"row 1 ports"?  "5 volts"?  Panasonic systems I'm familiar with apply 24V to the T&R line conductors (center 2 jack contacts).

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Re: Merlin Single Line Set
« Reply #16 on: July 15, 2017, 09:35:08 PM »
I'm using a Panasonic KA-TX624.

Ports 1-8 output voltage on the outer pair for the custom Panasonic phones (for programming, special features) - I have to be careful when I plug in older phones that have the third wire for ringing, as it shorts the line power, which then disconnects that line (until unplugged) (circuit protector) - a modular princess phone does the same thing...

I'm wondering if the integrated circuit or a transistor is shot on these (took a power hit)...  I'll get the multimeter out and try to trace circuits... (including the fuse I discovered...)

Jim
A phone phanatic since I was less than 2 (thanks to Fisher Price); collector since a teenager; now able to afford to play!
Favorite Phone: Western Electric Trimline - it just feels right holding it up to my face!

Alex G. Bell

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Re: Merlin Single Line Set
« Reply #17 on: July 15, 2017, 09:43:17 PM »
I'm using a Panasonic KA-TX624.

Ports 1-8 output voltage on the outer pair for the custom Panasonic phones (for programming, special features) - I have to be careful when I plug in older phones that have the third wire for ringing, as it shorts the line power, which then disconnects that line (until unplugged) (circuit protector) - a modular princess phone does the same thing...

I'm wondering if the integrated circuit or a transistor is shot on these (took a power hit)...  I'll get the multimeter out and try to trace circuits... (including the fuse I discovered...)

Jim
I know what a 624 is.  IIRC, the outer pair is power and a data link to Panasonic proprietary phones.

To be safe simply use a 2-conductor line cord to connect phones which have 4-contact jacks.  2-conductor line cords are easy to find or make if you have a plug crimping tool.

I doubt you will figure out much about the IC with a multimeter other than a blown fuse.

There may be a document on the Avaya site about these phones explaining the use of the outer 2 line jack contacts.  Might be for universal operation of the message waiting lamp.  It might work either by high voltage on T&R (RD & GN) or low voltage on the YL & BK jack contacts

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Re: Merlin Single Line Set
« Reply #18 on: July 15, 2017, 09:46:36 PM »
Unfortunately, all the phone does is ring. When picking up the handset, the phone continues to ring. Hopefully, it's just a blown fuse (unfortunately, the fuse is hard-wired...)
A phone phanatic since I was less than 2 (thanks to Fisher Price); collector since a teenager; now able to afford to play!
Favorite Phone: Western Electric Trimline - it just feels right holding it up to my face!

Alex G. Bell

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Re: Merlin Single Line Set
« Reply #19 on: July 15, 2017, 10:14:34 PM »
Unfortunately, all the phone does is ring. When picking up the handset, the phone continues to ring. Hopefully, it's just a blown fuse (unfortunately, the fuse is hard-wired...)
I'd expect it to be.  You should be able to easily determine its condition with the meter.

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Re: Merlin Single Line Set
« Reply #20 on: July 15, 2017, 11:36:14 PM »
Not the fuse - I'm tracing the circuit board, but believe it's the switchhook - on this phone, there's one pair that make and one pair that break when you lift the handset.  I'm having trouble with the pair that makes when you lift the handset - probably have a cold solder flow. The copper in the switchhook makes and breaks correctly.

  The catch is trying to trace the circuit underneath the switchhook mechanism - the circuits for that switch are under the plastic, so I can't see where they go, but so far, I'm not finding anything through the continuity tester of the meter.  I'm going to start drawing out the circuits as I track them down, but I get the feeling that it there's either a solder issue or possibly a trace that may have severed on the circuit board.

Time to put that engineering degree to work!

Jim
A phone phanatic since I was less than 2 (thanks to Fisher Price); collector since a teenager; now able to afford to play!
Favorite Phone: Western Electric Trimline - it just feels right holding it up to my face!

Alex G. Bell

  • Guest
Re: Merlin Single Line Set
« Reply #21 on: July 16, 2017, 07:33:11 PM »
Not the fuse - I'm tracing the circuit board, but believe it's the switchhook - on this phone, there's one pair that make and one pair that break when you lift the handset.  I'm having trouble with the pair that makes when you lift the handset - probably have a cold solder flow. The copper in the switchhook makes and breaks correctly.

  The catch is trying to trace the circuit underneath the switchhook mechanism - the circuits for that switch are under the plastic, so I can't see where they go, but so far, I'm not finding anything through the continuity tester of the meter.  I'm going to start drawing out the circuits as I track them down, but I get the feeling that it there's either a solder issue or possibly a trace that may have severed on the circuit board.

Time to put that engineering degree to work!

Jim
Often traces get lost under a component because there is a through-hole ("via") under the component where the trace changes to the other side of the board.  It may also occur at a terminal of the component under which the trace disappeared.   Sometimes "trans-illumination" (a bright light shone through the board or even applied to the edge) helps spot where a trace went.  Otherwise, unsoldering the component may be necessary to see where the trace went.  But that's rarely necessary.