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.