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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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Final Testing of a Rebuilt NuTone IM4006 Master Station

For my first Video entry, here's a simple video showing the operational checkout of a NuTone IM4006 Master Station after it was rebuilt. . . 


If you have comment about this video, please us this link to email them to me


Removing a NuTone Chime Module From a NuTone IM4006 Master Station

It's easy for me to tell someone to open up the Master Station and remove the Chime Module, but explaining how to do it is an entirely different matter.

Recently (yesterday) I spoke with Gregory, he has a Chime Module with very low volume.  He was reluctant to attempt the removal of the Chime Module, so i decided to show him how. . . in a video.

If you have ideas or comments on this video, please us this link to email them to me



How To Remove Your IM4006 Master Station - Video -

The NuTone IM4006 Radio Intercom Master Station is the second most common model we have sent to us for repair.

I have learened that owners find it somewhat daunting to open up their Master Stations and disconnect all of the cables and wires so it can be removed and sent to us.  They equally find it difficult to reinstall after they have received the rebuilt Master back.

After I have spoken with each customer about their repair, I send them a copy of the original Installation Instructions which gives the step-by-step instructions and diagrams to install their IM4006.  This works for many owners, but I thnk a video showing how to remove their IM4006 may be better.

Here is a short video showing the removal of a typically installed NuTone IM4006 Master Station.

I hope this video makes it easier for all of our customers.  If you have comments or feedback about the video, I am interesed in what you have to say.

Use this link to email me you ideas and comments




NuTone IM4006 & IMA4006 Cassette Players


The cassette player in a NuTone IM4006 or IMA4006 contains 129 individual parts, most of which are made from plastic.

The cassette player assembly is a complex electro-mechanical device which relies on an electric motor and drive belts to keep all of these parts moving correctly.  Devices like this cassette player use "mechanical logic" to control the functions of the player.

In simple terms, this means that all of the different parts inside player must be aligned and in their proper positions for the different functions to work at the proper time.

The most common complaint we have about the IM4006 cassette player is that the tape will not eject.  When the eject button is pressed the door will not open and the tape is stuck inside the player.

The usual course of action is for the user to pry open the cassette door with a screwdriver.  While this will open the door, it will also break the door latch and now the door will no longer stay closed. DON'T PRY OPEN THE DOOR!

Why does the cassette door refuse to open?  It's because of that pesky mechanical logic (remember, all of the parts have to be in their proper places for everything to work).

Inside the IM4006 cassette player there are 2 drive belts which are turned by a motor.  These belts turn pulleys, which in-turn drive gears, which in-turn move levers and so on.

When the belts stretch they slip, when they slip the pulleys, gears and levers don't move enough and the mechanical logic of out of sync and the player doesn't work correctly.

In the case of a cassette door that will not open, the cam that aligns the door release lever with the door latch did not move into its correct position when the "play button" was pressed, so when the "stop" button is pressed to stop the tape and then pressed again to eject the tape, the lever can not unlatch the door because it's not in the right position to do so.  Complicated, isn't it.

So, the belts are the key to the player working correctly.  This also makes them the number one problem with the cassette players.  They will all stretch and eventually they will all break.  Some times the belts will also dissolve into a black, gooey tar-like substance that gets all over the parts inside the player.  When this happens it's a real mess, but it can be cleaned up.

The second most common problem are broken plastic parts.  This is usually caused by normal wear-and-tear in players that have had lots of use.

(Blue arrow is the motor) 

Other problems can be with motors that have worn out to the point that they can no longer maintain the correct speed and the tape plays too slowly. The tape heads can also wear out from use as can the pinch-roller.

As with all of the other parts in a IM4006 or IMA4006, NuTone no longer has any cassette player assemblies to buy.  The number of individual parts that could have been ordered to repair the player was less than 12 and none of these are available either.

This is why we don't sell complete, rebuilt cassette players.  One used player can usually supply enough parts to repair 6-8 other players.  The only new parts we can source for these players are the belts.

See all of the IM4006 Cassette Player Pictures here