Sign of an expiring LCD screen

  kenwyn 21:21 26 Sep 2009

This has been happening for about a month now.. Each time I power up my LCD screen (a brand called LIKOM - about 6 yrs old now), it makes a loud 'electronic squawk/fizzing noise'. This is sometimes accompanied by the screen displaying only large random boxes of colour, or a severely distorted version of whatever the image should be. Usually switiching straight off and on again sorts it out. But is it on its way out? and is the noise it makes, together with the disorted image indicating it may be dangerous in any way?

  Audio~~Chip 21:25 26 Sep 2009

is the Power just a cord kettle lead that connects or so you have a seperate power ac adapter a bit like a laptop one that you plug in?

  kenwyn 21:31 26 Sep 2009

yes the power runs from the back of the screen to a black box, then out again to the mains, so via an ac adaptor

  mooly 12:18 27 Sep 2009

It does sound like a power supply/invertor problem. Most likely a dried out electroylitic capacitor or possibly "dry" soldered joints... too complex to explain here "why" it makes it do that, but a shame if that's all it is... the components cost peanuts.
The way of the world unfortunately, beyond economic repair I would guess.

  Audio~~Chip 21:34 27 Sep 2009

click here

The above is just one of many but its for Laptop instrucion not that different to replacing a TFT screen invertor. There was a excellent video on here a week or two ago. I will see if I can find it.

  kenwyn 07:06 28 Sep 2009

From your posts you seem to be inferring that the issue is with the external power cord? This is NOT hard wired in and therefore replaceable, so in response to the way I am reading Mooly's reply, the monitor itself is still OK?

  mooly 08:06 28 Sep 2009

If the cord is faulty I'm sure it would show up by waggling it around at the connector/plug ends. Give everything a good tap, monitor, adapter etc.
Whatever is happening sounds like it is "arcing", or that a major "corruption" of the voltages needed within the monitor is occuring.
A faulty invertor alone (the invertor produces a high voltage of several hundred volts that is used to power the backlight tube/s) would normally cause just a brightness or black screen issue. The fact that yours from what you say "corrupts" the data (random boxes of colour etc) suggest electrical arcing etc, possibly invertor related.
Does the noise come from within the monitor or from the adapter. Are there speakers in the monitor ? does the noise come from those.
Without actually seeing and hearing diagnosing at a distance isn't easy :)

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