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Do LCDs wear out?
31 July 2012 | by Do LCD displays wear out or fade with age?
The picture above shows the displays of my Elecraft K3 transceiver and my Kenwood TM-D710 VHF rig. The Elecraft display is sharp with good contrast and characters look almost black against the orange background. The Kenwood display is much less contrasty. The backlight is not as bright as the K3’s but the characters look more murky brown than black no matter how I set the brightness and contrast. It’s quite noticeable when the two radios are side by side.
I don’t think the Kenwood’s display was ever as bright as the K3’s but I don’t recall it being as murky as it is now. Whenever I look at it I keep wanting to turn the contrast up. I’ve taken to turning the backlight off altogether so it doesn’t bug me but there is no option to have it turn on automatically when a button is pressed. (AUTO BRIGHTNESS: ON appears to do nothing.)
My D710 has been running 24/7 for more than a year (with a brief hiatus when I went into hospital until I felt like running the APRS gateway again.) Could the display have faded (for want of a better way to describe it) over time? Or is my recollection that the text used to look more black than brown faulty?
4 Responses to “Do LCDs wear out?”
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I think what you have there is really two completely different display technologies. The kenwood is a dot-matrix type display, the K3 is of the silkscreened variety. Silkscreened always have better contrast because they only show segments where they’re screened, so they can run the contrast as hard as they want. If you do that with a dot-matrix display, you get a grey mess.
Or I may be all wet. 🙂
Julian,
The LCD panels I use on the job have a habit of fade as it were, at least there is an adjustment pot on the board to help. I have neither of the radios or the schematics, but if I did I would look around the display for one.
Tom
From ur pix it appears to be failing backlight. I’m not familiar with this unit, so unable to comment on ease of replacement.
Best to you,
GB
Many years ago I worked in the Motorola R&D group that had the task of trying to develop a LCD display. We found that the types of polaroid material (front and back of the display), thickness of the glass, type of glass,the back reflector material, type of LCD fluid, and drive voltage and frequency and shape all made a difference. The difference being sharpness, viewing angle, “brightness”, etc. Temperature also had an effect on speed and all the above too. So to compare one display to another is like comparing the technology in the KX3 to say a FT-817. They both can do HF CW/SSB/Digital….but they sure don’t play the same. This is true for ALL LCD technology. In the US at Walmart they have a wall of LCD TV’s. All on the same movie. All look totally different…but wait they are LCD’s right? Yes but not all the same, just like the simple ones in this article.
Hope that helps…
73
Harry K7ZOV