Is the Display on my IMA4406 Damaged or not?
Friday, April 18, 2014 at 7:38AM Recently I had a IMA4406 Master Station delivered to the shop for a repair and on the list of problems that the owner included was noted "Display Panel Defective. . . Please Replace".
I could see right away what they were describing, there was a discoloration "blob" in the middle of the display.
The blob wasn't within the LCD Panel assembly, it was actually behind the glass panel. (the blue arrow points to an actual defect in the LCD panel)
The display on a IMA4406 is a LCD (liquid crystal display) which is made up of 2 panels of glass with with the liquid crystals sandwiched between the panels. The information readout on the display is predetermined when it's manufactured, and it can only display the information in the readout mask (ie: AM FM, Clock Numbers, Disc-in symbol etc.) In the case of the IMA4406, the display cannot show random information that wasn't preset into it when it was made (it's not a "smart" panel).
The LCD panel is mounted on a plastic holder, which is mounted over 5 LED lamps , which are the back-light for the display. In-between the LED's and the LCD there is a plastic diffuser which evens out the light form the LED's, so there won't be any "hot-spots".
In the case of this IMA4406, some liquid got between the diffuser and the glass of the LCD panel and it looked like a blob.
To correct this, the entire IMA4406 was disassembled, the LCD panel was removed form the circuit board, the liquid was cleaned off all the surfaces and everything was reassembled. This took about 1/2 hour all together.
Something that will be a surprise to most people is that the LCD Display Panel is actually made of up clear (or slightly tinted) glass panels. When it's "turned off" you can see right through it. If you look carefully at the picture, you can see that I'm holding the panel in front of my bench meter and you can see right through it. . . cool.
Reader Comments (3)
I have IMA 4406 and it does not paly CD.
Disc rotates but can not hear music.
I hear beeping noise after disk stops rotating..
what can I do.
Otherwise radio plays quite well.
thanks
We just bought a home with a Nutone IM-4406 Intercom with Chime Module IA-28. The system worked fine the first day and I know the door chime worked and then all of a sudden the door chime stopped working. Everything else works fine. Would the chime just stop working or would there have been a warning. Any help would be greatly appreciated. I am not to well versed in electronics but is there a way to test to see if it's a bad chime?
Hi Bruce,
There are several possibilities as to why the chime has stopped working. The first thing you should try is performing a "reset " on the Master Station.
1. Open the right-hand lower door on the Master Station
2. Find the "loudness" switch, just to the left of the switch there is a hole in the panel. The reset switch is just behind the hole.
3. Use a small screwdriver or toothpick, insert it through the hole and push the reset switch, this is a micro switch so it doesn't move much, you will feel it go "click"
4. Keep the switch pressed for 5 seconds.
When you release the switch the Master Station will have been reset. You will need to set the clock and reprogram the preset radio stations.
Now try the door bell push button at the front door, does it work? if it does, your done, if it doesn't work, go on to the next item.
You could have a worn out push button.
1. Remove the Door Speaker Panel and locate the 2 wires that are connected to the back of the of the push button.
2. Remove the 2 wires and touch them together, if the chime rings, replace the push button. If it does not ring, you may have a wiring problem between the push button and the Master Sation
If you think it'a a wiring problem (after completing the above troubleshooting) send me a picture of the wiring behind the door speaker and a picture of how the wiring is connected. There may be a work-around for the wiring problem
If you download a copy of the Owners Manual for your IM4406, page 4 (#20) shows where the reset button is located
Thanks
Chris