Does MFM need external power supply?

[nydavid]

I've read all of the posts (2 years worth!), but still haven't seen a definitive answer on the need for external power for an MFM.

I just installed an MFM into an MLX-20D, without external power. I get no dial tone from the aux tel jack. Calls directed to the MFM extension (713, in this case) get a standard (slow) busy signal. Calls directed to ext. 13 ring on the MLX phone as expected.

System: Merlin Legend R7 V12 with 391C1 power supply.

I don't have the external power supply, so I can't try adding that. Previous posts have suggested that the MFM can be powered from the 008-MLX on pins 7-8.

I have the phone plugged directly into the port on the card with an 8 conductor station cord.

I've swapped: phones (i.e. reinstalled MFM in another phone), station cords (using different styles of 8 conductor jumpers), ports.

I carefully checked that the MFM jumpers are set correctly.

Using WinSPM, I can see ext. 713 and its programming seems normal. I did not do any system programming after installing the MFM, since it didn't seem anything was needed.

This is my first Merlin Legend, so I've just followed the documentation to get everyting working.

Even the Merlin Messaging VM was simple to install. I'm just stuck on this MFM.

I'd hate to send the MFM back as broken without some better way to prove that it's bad.

Any help would be greatly appreciated!

 

[cvrbob]

yes you need it

 

[cvrbob]

AT&T pwr KS-22911 L1/L2
input 120V. 60 HZ. 24W
output 48VDC. 200mA.
plus you need adapter 400B d

 

[merlinman]

OR - all 4 pairs coming to the phone.

 

[nydavid]

Yes, merlinman, I do indeed have all 4 pair coming to the phone, since I've plugged the phone directly into the 008-MLX port with an 8-conductor straight thru cable.

Still, it doesn't seem to work.

To better understand your response, I wonder why you suggest 4 pair, when my Merlin Legend Installation Guide has a wiring diagram that shows pins 1 and 2 as N/C. Power seems to be on 7/8. Do you think that with my current 4-pair connection not working, I'm looking at a dead MFM? Or, as cvrbob suggests, I MUST use the external power supply?

 

[aussie88]

It is true that pins 1 and 2 are worthless, however, for some reason or another, Avaya made it so you still have to use an 8 wire cable to gain access to the power pair. Oh yeah, and just some advice that someone else on here (Thanik you TTT) told me. With Avaya Legend and Magix systems, never ask WHY something is the way it is. Just accept everything the way it is, because anything else will drive you nuts. Try another cable. If the MLX-20 has a DSS on it, you will need external power, however, without a DSS, the brown pair should work just fine. If you plug in directly to the control unit, switch phones, switch cords, switch ports, check those jumpers, and still no go, I would have to say it is a bad MFM.

 

[merlinman]

I guess I missed the part where you said you were plugged directly into the Control Unit.

Just make sure your test there is with a standard D8W Mounting Cord.

 

[cvrbob]

the fourth pair on the MLX port is for the second B channel assigned to the telephone for voice announce over busy & for the MFM , you need external pwr which adds pwr. to the green pair for MFM

 

[aussie88]

Nope, cant go with that. On the ATL sets, the brown pair is for OHVA. But on the MLX sets, it is for power. And I am pretty sure that power cones in on the BROWN PAIR.

 

[cvrbob]

mark as the Brown pair

 

[cvrbob]

my mistake to fast on the fingers , on the atl set you needed 2 stations to make vaob, main sta on brown looped fron next station w/blue took up alot of stas, but on a mlx port the brown does it all, DSS ,VAOB,MFM using the second b channel, but with the Dss & the MFM you need external pwr.

 

[cvrbob]

granted you should get it to work at the control unit with out external pwr, but when you send it any distance you will most likely need the pwr.

 

[cvrbob]

went back and looked at the pocket reference books they used to give us techs , unit load rating on tele & adjuncts, is more confusing , its shows that a dss can be powered from the control unit carrier, (could never get it do that ) MFM is powered by individual wall power unit located at the station, (we could get by without one in the phone room ) for fax, but at another 3 station at the other end of the office needed external pwr. for the MFM to work( it could be load factor ) but they are in 3 different carriers was also suprise to see that headset adapter pull in 1.0 ( must be 502's have none ) load & plantronics m10 & 12's use we have alot of them,but they have batteries & no lights except for status , the dss shows a factor of o.9 MFM a 1.3 SO check your pwr. unit load + all are 391C1

 

[nydavid]

Thanks all for the helpful advice. To further describe my setup:

MLX-20D had no DSS, just MFM.
Other phone tested was MLX-10D, in case the MLX-20D was drawing too much power.

There is only 1 cabinet. It is lightly loaded. For this test, there are only 3 phones plugged in: 1 MLX-20D (no DSS, now without MFM), and 2 MLX-10D, one with MFM. Power supply is 391C1.

I'm NOT using a D8W cord, since I have none. I am using CAT 5 cable with RJ-45 connectors and all 8 conductors in a straight through configuration. The phone is just a few feet from the port connected with 5 feet of cable, and I tried a few different cables just to be sure.

 

[aussie88]

Hmmm, this is odd. A regular CAT5 cord should cut it. Well, try external power, if still no go, it sounds like a bad MFM. Actually, I already think it is bad.

 

[SYQUEST]

Hi nydavid,

What is an MLX-20D? The only 20 button MLX phone I know of is the MLX-20L. Could not find any "20D"s in the manuals.

To clear up confusion again on the set wiring on the LEGEND, there is table A-4 in the R1 Legend install manual that shows all the contact assignments for MLX & ATL phones and their functions. You can download the manual from Avaya's site. (I tried uploading to this post but the browser would not allow it)

Hope this helps!

....JIM....

 

[nydavid]

SYQUEST, thanks for the correction on the MLX-20L. My fingers where out of sync with my brain. Of course there is no MLX-20D. I meant to say that my MLX-20L had no DSS attached.

I do have the wiring diagram you mention, which is my source for concluding that pins 1/2 are not connected and all power is on pins 7/8, which should power the MFM.

Just to be sure, though, I have all 8 wires connected because, hey, you never know!

 

[jinxs]

there are as well jumper settings on the MFM to either make it a t/r device or an SAA. If you have it set-up as an SAA you would not recieve any dialtone. You can find the docs on the AVAYA website...too confusing to decribe here.

 

[aussie88]

You said that you had checked those jumper settings through and through. Check em again, and see if it works.