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Main | Final Testing of a Rebuilt NuTone IM4006 Master Station »

NuTone Model IM4006 Radio Cassette Intercom

Exciting news for the music lover and those with discriminating audio tastes! The finest audio you can imagine in a home-communication system is yours. . . from NuTone.

The IM4006 was introduced in 1986 and quickly became the most popular music intercom system that NuTone had ever made. The IM4006 was based on a new platform that began with the IM3003 in 1984 and that platform design was used through the end of 2006.

The IM4006 featured a cassette tape recorder that doubled as a family message center, allowing any user to leave a voice message for family members to listen to.

The IM4006 was the very first model of music intercom to feature a true digital radio tuner with electronic scan tuning, 10 programmable radio station presets and a digital clock and radio frequency readout.

Since the IM4006 is a 6-wire system, it features “hands-free” reply intercom functions and remote stations including a “Privacy” button to block unwanted listening into that room.

The standard IM4006 was designed to accommodate up to 9 remote stations, but with the IA410 Expansion Kit, the maximum number of remotes increased to 20.

The IM4006 was a very reliable system right from the beginning with the exception of a new type of wire that NuTone introduced for the IM4006. The new wire was NuTone's IW6R, the “R” stands for ribbon.

This ribbon wire was a attempt to make the installation of the IM4006 easier and quicker, the exact opposite is what really happened.

The original IW6R was a flat, 6-wire ribbon cable that had solid wire inside the ribbon. The insulation that made up the ribbon was thin and it could be easily damaged during the pre-wire of a new home.

Installers were accustomed to IW6 cable, which is strong and pulls easily through pre-drilled holes in construction framing. IW6R ribbon wire is almost 1 inch wide and unless the pre-drilled holes are extra large, the edges of the cable will be damaged when the cable is pulled through the holes. It was not uncommon to have several cable runs in a single house have damaged wires.

The IW6R used crimp-on connectors that were included with each remote speaker. These connectors were to be crimped on to the ends of the IW6R cable when the system was trimmed out.

Installing the connectors required reading the directions (not a popular thing for installers to do) and some amount of finesse in preparing the cable and crimping the cable (also not a popular skill with installers).

A well-done intercom trim-out could be completed in half the time compared to using cable with indivisible wires.

Another feature that made the IM4006 so popular was starting in 1986, NuTone offered a “Life-Time” Warranty on all of their intercom systems. This warranty included Parts, Labor and In-Home Service for any problem with the systems. I personally performed many hundreds of warranty calls which were just to replace crimp-on connectors.

The IW6R cable was modified to use stranded wire in the cable which eliminated the potential of the crimp-on connector not making a good connection to the wire. It did not solve the “installer skill” issue. Around 1991 NuTone abandoned IW6R cable and the newly revised IMA4006 went back to standard IW6 cable with its individual wires fastened to screw terminals.

While NuTone choose to only label this model as the IM4006 and later the updated version became the IMA4006, there are actually 3 different variations if you look at the circuit board changes from 1986 through 1996.

The breakdown for the 3 variations is roughly:

1986 – 1987 Original Version Boards

1988 – 1991 1st revision of amplifier/power supply, intercom control and master control boards.

1992 – 1996 2nd revision of amplifier/power supply, intercom control, master control, terminal board and function selector boards.

There is not a lot of interchangeability between the 3 variations listed above. Intercom control boards can be used on all 3 variations, but amplifier/power supplies and master control boards cannot, and should be considered as “sets”.

The boards and assemblies that remained mostly unchanged throughout its production were the radio tuner, memory/display, cassette player & pre amp boards. These parts are interchangeable on all versions made from 1986 through 1996.

(The IM4006 is a complicated unit with many circuit boards and interconnection cables)

See all of the IM4006 pictures

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Reader Comments (49)

Hi Kevin

We have resigned the door hinges to make them more reliable and they are in production now. As soon as we receive them and test them for quality, I will post an article about them.


July 24, 2014 | Registered CommenterCindy & Christopher

re model Im 4006. Very faint sound heard on the master speaker but can't increase the volume. Disconnected all the wires to take to a repair shop, couldn't get the system to work so brought it back home, reconnected it and the radio worked just fine for about two hours then back to square one, no volume. Tape plays with good volume. Antenna problem ruled out. Intercom is ok. Any suggestions?

August 11, 2014 | Unregistered Commenterjoe

Hi Joe,

There could be several causes for the problem with your IM4006. Please fill out an Intercom Repair Request Form (located in the NAVIGATION HEADING on every page of this site) and once I receive it, I'll contact you directly about your IM4006


August 11, 2014 | Registered CommenterCindy & Christopher

Are the hinges for IM4006 now available?

August 17, 2014 | Unregistered CommenterRao

Hi Rao,

Our replacement hinges are in route to us at this time

August 21, 2014 | Registered CommenterCindy & Christopher

We love our IM4006...however the volume knob just broke off.
How do I replace it?
Thanks so much.

October 25, 2014 | Unregistered CommenterPhil

Hi Phil,

Broken volume slides are a common problem on the IM / IMA4006. The actual volume pot becomes very stiff and hard to slide, so greater and greater force is required to move the control. This stresses the plastic slide and eventually it breaks off.

The original volume slides are no longer available from NuTone, however we have had them reproduced. Installing the slide requires some dismantling of the boards in the IM4006 and it's to complicated to describe in a post here.

Please contact me by phone and I can explain it to you. Remember that the underlying problem of the volume pot must be addressed, otherwise the problem will reoccur.


October 27, 2014 | Registered CommenterCindy & Christopher

Regarding the two lower panels on the IM-4006 system that cover all the individual speakers buttons it has a very poorly designed hinge which 3 out of the 4 have cracked apart. Do you know where I can get replacement hinges or if there is a retrofit hinge to replace? UPDATE: I was able to make two hinges from 90 ohm TV antenna wire. Remove some of the material between the wires and bend wires at 90 degress opposing to fit in hinge catch area of the unit. In the side that attaches to the door, drill a hole and use screw to attach. Cut and trim replacement hinge to size of manufacture's broken hinge. Works great and in my case a white 90 ohm wire blends in un-noticed with my unit. Kevin

October 30, 2014 | Unregistered CommenterKevin

I have the IM-4006 unit and it has been working great for 20 years..... until when recently the speaker unit in the basement stopped working. I've switched the ribbon wires and the other unit works, but the speaker in the basement still doesn't. So its not the main unit. I tried a working unit in the basement and that didn't work either. So it has to be the wiring, I'm thinking. Not sure how to test which end went bad or how to text/fix the ribbon connectors.

November 25, 2014 | Unregistered Commenterdaveh

Hi Daveh,

The crimp on connectors that are used on the NuTone IW6R Ribbon wire are "single-use" items. Once they have been crimped closed on a piece or ribbon wire, they should be used again.

We keep the crimp connectors in stock and you can get replacements from us.

There is also the possibility that the actual ribbon cable has been damaged. The simplest way to test this is to check the cable for any short circuits between the 6 conductors and the by checking for any broken conductors in the cable.

You will need either a Ohm Meter or a Continuity tester for these tasks.

For more detailed help, please call me to discuss these problems


November 25, 2014 | Registered CommenterCindy & Christopher

Chris, I have the Nutone IM 4006; suddenly, the door chime has become very faint; almost inaudible. Any quick fixes?

December 13, 2014 | Unregistered CommenterGreg

Hi Greg,

How easy of a fix this may be depends on what is the root cause of the problem. Common causes are as follows:

1. All of the Volume Control on all off the Remote Stations and Master Stations are turned down below 50%. This is done either because the system is generally out of adjustment or because there is a lot of background hum on the system (which is annoying) so the speakers were turned down so you can't hear the hum.

2. You system has failed beyond the basic "Background Hum" stage and even with all of the settings at maximum the Chime, Radio and Intercom have almost no volume.

3. Only the Chime Module Volume is very low, (the radio and intercom volume is fine) this is a chime module failure, which can be repaired.

To narrow down the root cause, more detailed information about your system is needed.

Please fill out an Intercom Repair Request Form (located under the NAVIGATION HEADING on every page of this site) and once I receive it, I'll contact you directly about the problem with your system


December 15, 2014 | Registered CommenterCindy & Christopher

We corresponded back on Oct 27th about our IM4006 Nutone volume control knob. I've limped along but would like to fix if possible.
Your comment about having to dismantle the board scared me...but ready to take on with your guidance.
Please advise.

March 5, 2015 | Unregistered CommenterPhil

Hi Phil,

Please call me when you have the chance to discuss this type of repair


March 5, 2015 | Registered CommenterCindy & Christopher

I have a Nu Tone Radio Intercom Model IMA4006 Series. I need to replace door hinges that broke and also a volume control slide button on the master unit. Is this possible?

October 17, 2015 | Unregistered CommenterJudy Wolter

Hi Judy,

We have both Door Hinges and Volume Slides available.

Please call me to discuss the installation of the Volume Slide


October 19, 2015 | Registered CommenterCindy & Christopher

Hi , we recently purchased our home with the Nutone music intercom IM 4006. The static from the speakers is driving me crazy. What system could we use to replace this? Thanks , Bonnie

February 13, 2016 | Unregistered CommenterBonnie

Hi Bonnie,

You could replace the IM4006 with the new NM200 system, however you would have to replace all of the remote stations as well.

If the only real problem with the IM4006 is static on the remote stations, a simple cleaning of the controls will likely solve the problem.

You can go to our YouTube Chanel and watch out Video that shows how to clean the controls in your remote stations


February 16, 2016 | Registered CommenterCindy & Christopher

M y IM 4006 is I believe 27 years old and was making a sound like the cassette was running, but it was not. I live in Ontario, Canada, about one hour from Detroit. Is there anybody that could repair or install a replacement that you know of in Ontario? Thanks.

August 7, 2016 | Unregistered CommenterDon G.

Hi Don, It may be that the cassette motor is running, but the belts are broken and the drive assembly that moves the tape is not moving.

We have a YouTube Video that shows how to remove the cassette assembly from your IM4006. In the Video I show how to disconnect the power form the Cassette Player, which will turn it off

Here's a link to the Video:

I don't know anyone in Canada that I can send you to for service, You can always remove the Cassette Player and send it to me for repair


August 8, 2016 | Registered CommenterCindy & Christopher

I may have shorted the system out! I was having a large hum from an outside remote and disconnected the speaker - I have a feeling I must have shorted it before I could wrap the wire because the intercom/doorbell side is now dead. Is there a fuse protecting the system or have I now made a minor problem into a big problem?

February 1, 2018 | Unregistered CommenterDave Shehane

Hi Dave, It is unlikely that you shorted out the system by disconnection the patio station. There are no fuses in the IM4006.

Was the humming just on the Patio Station or was it on all stations if their volumes were turned up? I suspect that the problem was everywhere (which is typical).

You can contact me directly to discuss the problem in greater detail


February 2, 2018 | Registered CommenterCindy & Christopher

Chris, thanks a lot for posting this. The buzzing on my IM4006 is driving me crazy. Unfortunately, I am located in Canada so I'm not sure how to safely ship the unit to you for repair. I have some experience with soldering/desoldering PCBs and am planning to attempt this myself. Do you have a parts list of the capacitors and voltage ICs that need to be replaced? Also is it possible to order volume sliders and hinges from you? Thanks!

March 15, 2018 | Unregistered CommenterShaun

Hi Shaun,

We have customers send their equipment from Canada all the time without any problems. If the Master Station is packaged carefully and shipped with UPS or FedEx, the chance of it getting lost are small.

I do not sell components and and my schedule does not afford me time to be involved in do-it-yourself repairs

If you are interested in having your IM4006 repaired, I will need some more specific information about your system.

Please fill out an Intercom Repair Request Form and once I receive it, I'll contact you by phone to discuss the problems with your IM4006 and its repair


March 16, 2018 | Registered CommenterCindy & Christopher

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