Need to replace LED display for a Memorex Mi1200 iPod dock/CD player/radio

Discussion in 'General Electronics Chat' started by Scott_in_Benton_Arkansas, May 20, 2016.

  1. Scott_in_Benton_Arkansas

    Thread Starter New Member

    May 20, 2016
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    I have a Memorex Mi1200 iPod dock/CD player/radio (manufactured Sep 2008 in China; distributed by Imation) in which the LED display no longer works. I want to replace the display board and need the specs.

    Memorex Consumer Electronics support so far cannot provide the specs. The external display dimensions are about 2.75 inches by 1 inch (about 7 cm by 2.5 cm), and I can see that the circuit board inside the chassis is quite a bit larger.

    Can anyone direct me to where I can obtain those specs and, ideally, the part itself or a suitable substitute part?

    Sincerely,

    Scott
    Benton, Arkansas, USA
     
  2. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Photos?
     
  3. Scott_in_Benton_Arkansas

    Thread Starter New Member

    May 20, 2016
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    Not yet; I haven't disassembled it to that point.

    If photos of the display board would be a tremendous help, let me know.
     
  4. Scott_in_Benton_Arkansas

    Thread Starter New Member

    May 20, 2016
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    P. S.
    This additional info should help: The clock works, and the main display, to my knowledge, shows all messages in addition to the time, which means that the dark LED segments and custom symbols all display properly. (I can only see them with a flashlight, given the unit's design.)

    What doesn't work is the blue back-lighting with one exception. Below the main display are three small indicator lights for each of the three functions: iPod, radio or CD player. Only the leftmost (for the radio) will light up, when I select the radio function, with the bright blue light that would normally illuminate the main display and the other two indicators. Regarding the main display, does this suggest a malfunction in an LED-backlit LCD behind the screen?

    I'll need to disassemble the unit significantly to take the photos, which I'm willing to do, but I'll first await your reply in light of what I've just shared.

    With thanks,

    Scott
     
  5. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Digi-Key, a major national distributor of electronic components, has over 3000 different LED character and numeric displays; so, yeah, photos would help.

    ak
     
  6. Scott_in_Benton_Arkansas

    Thread Starter New Member

    May 20, 2016
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    Thank you, AK. I've realized this morning, and I'm embarrassed to say, that I should have used "LCD" instead of "LED," but I am an electronics novice.

    Another contact has suggested that there are tiny grain-of-wheat lamps that illuminate the LCD and indicator buttons, which makes perfect sense, and that the display is a transmissive LCD.

    I'll disassemble and send photos when I can.

    Scott
     
  7. AnalogKid

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    Aug 1, 2013
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    You need to determine what is broken, the LCD device or the backlight. If you look at the display under bright light while running, you should be able to see the digits even with no backlight if the LCD is working but unlit. But be prepared - displays in low cost mass produced items are almost always custom designed for that device, not catalog items, and once the initial production run is completed that's it forever.

    ak
     
  8. Scott_in_Benton_Arkansas

    Thread Starter New Member

    May 20, 2016
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    Thanks, AK, and I hear you about that last comment.

    The LCD device seems to be working perfectly, as I can see all the symbols and segments with the aid of a flashlight. So, the backlight is quite likely the culprit, and its malfunction suggests an original grain-of-wheat bulb. I'll be happy to retrofit the backlighting with something appropriate (or perhaps even illuminate the LCD from the front). I'm about to disassemble the unit right now.
     
  9. Scott_in_Benton_Arkansas

    Thread Starter New Member

    May 20, 2016
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    Disassembly of the display board requires removing three layers of screws and their associated boards, not to mention disconnecting several wires and cables. I've been able to remove the unit's front plastic cover (smoke-tinted) and the gear assembly that operates it without trouble, and I notice that the LCD works fine and is easily readable with ambient light. In fact, all three indicator lights actually work when the iPod is attached and a CD installed. (I bought this unit used so have no prior experience with its operation.)

    The back light must be located on the front of the display board (which I can't see from the inside) and soldered in place, so I'd have to remove that board just to have a look. Because that seems like too much work for a novice and problematical to fix, and because I can correct the issue by cutting a rectangle out of the front plastic cover in front of the LCD display, I'll try that first.

    I'll return if I have to resort to electronic surgery, but regardless, thank you very much for your input, AK!

    Scott
     
  10. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Are you sure it has a backlight? Did it literally glow in the dark?
    Seeing the segments is not enough. All segments are visible when the display is unpowered when viewed under the right lighting. But if powered and working but not backlit, you should be able to see *characters*. For example, a 2 should look like an 8 with six of the segments a little bit darker than the other two.

    ak
     
  11. Scott_in_Benton_Arkansas

    Thread Starter New Member

    May 20, 2016
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    [​IMG]
    Hi AK, and yes. It normally looks like this when backlit.
     
  12. AnalogKid

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    Those are blue LEDs, not grain of wheat incandescent bulbs.

    aka
     
  13. Scott_in_Benton_Arkansas

    Thread Starter New Member

    May 20, 2016
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    Thank you, and that makes sense. Still, the LEDs aren't visible from the back of the display board, although I suspect that I can see the stubs of their leads soldered in place. Instead of removing that board just to have a look, I'll see if I can carefully cut a window in the front cover (the cover has a thinner section immediately in front of the LCD) and live with the ambient view of the LCD's segments.
     
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