The 10 most common problems with a NuTone IM /IMA3003 Music Intercom System
Thursday, September 13, 2012 at 9:21AM The IM/IMA3003 Music Intercom System was in production from 1984 through 1994. During this time there were many electronic updates to the fundamental design of the 3003.
The 3003 is a 3-wire, home-run wired system which has room-to-room intercom functions, entry door communication, built-in AM/FM radio and a digital clock.
The models manufactured in 1984-1985 use different amplifier/control and selector control boards than the later versions. With the increased popularity of built-in Chime Modules, a change was made to allow the homeowner to take better advantage of this new option.
To be able to hear the Chime Module throughout an early 3003, it was necessary to leave the power switch in the ON position. If if the power switch was in the OFF position you would not hear the chime tones. A change was made in 1986 which allowed the chime to be heard regardless of the power switch position. There was a Factory Modification to convert early models if needed.
The 3003 does have a true digital clock, however it has an analog (mechanical) tuner. The tuner is connected to the digital display for convenience, but it is not a digital tuner.
There are Room Control Switches behind the door which surround the clock. Behind this door are the Intercom Volume and Tone Controls along with buttons to set the clock.
The 3003 uses 25 ohm speakers throughout the system.
Inside remote speakers are Models:
IS/ISA305: Small inside stations with 5" speaker cones, Ivory, White, Faux Wood Grain
IS/ISA308: Large inside stations with 8" speaker cones, Ivory, White, Faux Wood Grain
Inside wall mounted Remote-Controls:
IC/ICA301: A small wall station with volume and intercom control, no built-in speaker
Inside Remotely mounted Ceiling Speakers:
IS76: A round Ceiling Speaker with a 8" speaker cone, used with IC/ICA301 remote control
IS75: A round ceiling speaker designed to look like a recessed light fixture with a 5" speaker cone.
Inside Volume Controls:
IC901: A wall mounted Volume Control used when creating a Music-Only location.
Cindy & Christopher
POWER SUPPLY PROBLEMS:
The #1 problem with 3003 systems has to do with failed power supply components on the Power Supply/Amplifier/Intercom Control circuit board.
When the 3003 was new, if you listened carefully to any speaker, you would hear a light background hiss. This is white noise. White noise is the background noise an amplifier makes when it is turned on.
As the 3003 ages, the hiss becomes a hum, and as time passes the hum becomes louder and then turns into a buzz. These changes in the sound are due to the gradual failure of the components in the Power Supply.
As the 3003 reaches the complete failure state, you will notice that the radio, door chime and intercom functions will not work, although the clock will still show the time. If you turn the radio power on and switch the input selector to FM, you will notice that the numbers on the display will continuously change, as if the display were counting.
If left in this condition, the 3003 can have a dramatic failure which will cause greater damage to the amplifier.
THE SOLUTION:
Rebuilding the Power Supply in a 3003 is a fairly simple task for a NuTone Service Center. It consists of replacing 10 capacitors and 4 diodes.
More repair will be required for sets that have been left powered up after they have failed.
THE OUTCOME:
After rebuilding the power supply, the 3003 will be restored to its original condition, with only a slight hiss of white noise at each station. This type of repair will extend the life of the of the 3003 for another 10-15 years.
Inside the red box are the power supply capacitors. All of the blue arrows point to the newly installed parts. There are 3 additional capacitors located on the other side of the heat sink.
Here are all of the old capacitors.
Cindy & Christopher
CHIME MODULE PROBLEMS:
The 2nd most common problem with a 3003 has to do with installations that include a chime module.
Chime modules are Models are:
IA28 which is a 1-2-8 note chime module.
IA29 which is a musical chime module.
When a chime module is installed in a 3003, the interconnect cable is plugged into the Switch Control Board. This 4-pin connector supplies power to the chime module and makes the audio output connection from the chime module to the 3003.
Chime modules have a high gain output (high signal level) and that signal is fed into the switch board through a pair of transistors. Some times when a chime module fails, it will feed DC voltage into the switch board input and cause the transistors to fail.
Chime module failures are not uncommon field service requests. Even thought the chime module has failed the service person will find that a new module will not solve the problem. The switch board failure must also be corrected.
Reader Comments (113)
Hi Chris and thanks for this site. My 3003 has experienced the power supply failure, perhaps the more catastrophic version. I have replaced the suspect capacitors. The diodes all checked good. When I powered it up the clock illuminated for a few minutes and then went dark. After a few seconds, the 1 ohm 2W resistor started smoking. I have determined that the 882 regulator transistor is drawing 200 mA of base current which seems high. The transistor tests good, but the output voltage is high, around 20 volts instead of 14.5. The 7805, however is handling the higher input voltage and generating 5 volts. My board is an HCT-4A and has an additional diode, D-132 with the cathode to the 882 emitter and the anode on ground. Neither the schematic or parts list you so kindly furnished shows this part. The board has a zener symbol for it. I can't figure out why there would be a zener diode from the 14.5 rail to ground. Also, the schematic shows the audio amplifier only powered up when the power switch is pressed on but my circuit board indicates it is always powered. I suspect the audio amplifier is bad, but have not yet pulled it to see if it is the source of the overcurrent.
Do you have any comments or suggestions for my troubleshooting process, and can you identify D-132? Can you estimate the cost of a repair?
Thanks,
Al
Hi Al,
D132 is a 18 volt 1 watt Zener Diode. Your board is very different than the original schematic that NuTone originally released. Unfortunately they never release any updated schematics.
I will need more detailed information about your system to provide a repair estimate. Please fill out an Intercom Repair Request Form (found in the left-hand index column) and once I receive it, I'll contact you to discuss the problems with your IM3003 and its repair. - Chris
Hi Chris. Do you guys provide replacement coils for the door speaker? I've eliminated all other points of failure and I've come to the conclusion that the coil must be at fault, but I can't find a replacement or equivalent for a OUAZ-SS-116D. I can find 12V coils, but not 16V.
Hi Arin:: You will need to contact me directly about the part you're looking for - Chris 925-743-8236
I have an old 80's intercom and it is clickety clicking all the time??? What can I do...please e-mail me directly for help....
Am in the process of trying to get my 3003 system working. Finally got the front door unit to ring. However, the chime volume is really low. I've turned up the volume on the circuit board fully, but makes no difference. It's audible, but seems like it should be louder. Will replacing the chime board make a difference?
Hi Mike,
How is the volume of the radio with the Master Speaker Volume Control set at full and the Program Volume set between 1/3 and 1/2?
If the radio volume is very low with the adjustments set this way, you have a problem with failures in the IM3003 Master Station
If the radio volume is fine with the adjustments set up this way, you can increase the volume adjustment on the Chime Module (we have a YouTube Video that show how to do this)
If the Chime Module is faulty - it should be repaired not replaced
Chris
My chime volume suddenly became very low on IM-2003 with IA-28 chime module. Rodio volume is fine and can be adjusted normally. The chime volume adjustment was not changed to cause the problem but I have since turned it to max and it is still very, very low. Is this a problem with the chime module itself?
Hi Larry,
There are many possible causes for the low chime volume with your IM2003.
It could be any of the following or a combination of these common problems:
1. Chime Module problem
2. Chime signal input on the main IM2003 circuit board
3. A failing power supply
It will take some detailed troubleshooting to find the source of the problem
You can contact me directly to discuss what need s to be done
Chris
925-743-8236
Hi Chris, I have an M&S 200 built in the 80's. Every couple of months it intermittently makes a clicking noise and drives us crazy. I replaced the door bell because I thought that may be the problem because of moisture, but that has not solved the problem ! When I hold the listen button down on the master unit it seems to stop Please Help ! Thanks
Hi Debra, While this is off topic because your M&S System (Music & Sound) is no a NuTone System - I will try to help
The clicking sound you're hearing is coming from the Intercom Relay inside the Master Station. The relay is responsible for switching the direction of the Intercom Conversation (Talk & Listen)
When the relay is activating by -its-self, it is usually being caused by a dirty or corroded Intercom Switch on a Remote Station (not even the Door Speaker)
I would suspect outdoor Patio Stations first, since they have been outside in the weather for more than 30 years.
Cleaning the controls in the Remote Stations with DeOxit D5 will probably help the situation
I hope this helps
Chris
Hi Chris,
I purchased a home and it came with IM-3303 system with 4 internal speakers, one door bell speaker, and one patio outdoor speaker. It worked fine for a few years. However, recently, one indoor speaker is not working well. One can intercom to it, ie. can hear sound from another speaker/master but no sound going back (one direction). I tested it with another good working speaker from another room and the result is the same. FM music works on all speakers. Is this a wiring problem or something is wrong at the master panel? It is hard to think it is a wiring problem specific to that speaker because one way intercom seems to work.
Hi Andy,
If you have the music playing and try to initiate a call form the the remote station that you're having a problem with, does the music mute when you press the Inside / Patio talk Button? - I'm going to guess that it does not. . .
This would indicate a broken or disconnected "Blue" wire between that station and the IM3303 - this causes the Intercom Function to be disable from that station
You can still hear calls coming into that station because the incoming calls are on the Radio side of the system
Chris