Hello to all the community,
My name is Javier and I am from Madrid (Spain), so English is my second language, then I would like to apologize in advance for any grammatical or mispelled words. Also I am at my least year of telecommunications degree specialized at electronics that maybe on Europe and USA is the same as electronic's engineer, so I think I have the background, knowledge and skills needed to try to fix the problem of this monitor (also I've done some maintenance like ~4 years ago on another electronics devices for a company).
Like a year ago my T220HD monitor started to display some noise horizontal bars at the display (hdmi, vga, dvi, YCrCb, TV, etc) on bright colours with clearly noticeable ones on whites, like the ones you can see at my gallery at photobucket:
http://s934.beta.photobucket.com/use...T220HD%20issue
(if you would require closer images or any macro of a cap, please, don't hesitate asking me because I have a much better camera right know to do so)
At the beginning, they appeared time to time and then oftenly till every time I turn on the monitor, they appeared. So, I thought that it has to be an issue with the main board, because I've inspected the power supply board without any leakage on the 'Sam Young' capacitors (as some users around the net reported but without image (black screen) or another issues). I haven't checked the voltages 'cos I wasn't sure of what values expect as an ok reading (or at least, between the margins).
Last week, 'cos we thought to get a chance into replacing the main board to fix the monitor in order to use it, I've ordered an indentical main board from SJS TV Services (one week delivery from UK to Spain, everything ok) and it arrived today. I've switched the main boards obtaining the same result.
So, I've decided to make some readings about the voltages attacking the screen (because I suppose that the ones attacking the main board were ok, the one bunch of black + 1 red cable) and I've read ~7V AC and a little offset ~200mV DC at CN304 and CN303. Also, I have the service manuals which I upload you to my dropbox in case any reader would need them (no profit or advertisement intended):
https://dl.dropbox.com/u/50215883/sa...dd_ls22tdd.rar
and I haven't managed to find the voltages or the full diagram of the power supply board in a quick first look (also 01:15am doesn't help a lot, you know). So, do you have any clues / ideas about what is happening to my t220hd (yes, it had surpassed the warranty like 2 years ago so it will be no problem replacing a component)? Maybe is it the circuits of the matrix of the LCD and I have to order a LCD replacement (which maybe is not worth)?
Thanks a lot
Javier
My name is Javier and I am from Madrid (Spain), so English is my second language, then I would like to apologize in advance for any grammatical or mispelled words. Also I am at my least year of telecommunications degree specialized at electronics that maybe on Europe and USA is the same as electronic's engineer, so I think I have the background, knowledge and skills needed to try to fix the problem of this monitor (also I've done some maintenance like ~4 years ago on another electronics devices for a company).
Like a year ago my T220HD monitor started to display some noise horizontal bars at the display (hdmi, vga, dvi, YCrCb, TV, etc) on bright colours with clearly noticeable ones on whites, like the ones you can see at my gallery at photobucket:
http://s934.beta.photobucket.com/use...T220HD%20issue
(if you would require closer images or any macro of a cap, please, don't hesitate asking me because I have a much better camera right know to do so)
At the beginning, they appeared time to time and then oftenly till every time I turn on the monitor, they appeared. So, I thought that it has to be an issue with the main board, because I've inspected the power supply board without any leakage on the 'Sam Young' capacitors (as some users around the net reported but without image (black screen) or another issues). I haven't checked the voltages 'cos I wasn't sure of what values expect as an ok reading (or at least, between the margins).
Last week, 'cos we thought to get a chance into replacing the main board to fix the monitor in order to use it, I've ordered an indentical main board from SJS TV Services (one week delivery from UK to Spain, everything ok) and it arrived today. I've switched the main boards obtaining the same result.
So, I've decided to make some readings about the voltages attacking the screen (because I suppose that the ones attacking the main board were ok, the one bunch of black + 1 red cable) and I've read ~7V AC and a little offset ~200mV DC at CN304 and CN303. Also, I have the service manuals which I upload you to my dropbox in case any reader would need them (no profit or advertisement intended):
https://dl.dropbox.com/u/50215883/sa...dd_ls22tdd.rar
and I haven't managed to find the voltages or the full diagram of the power supply board in a quick first look (also 01:15am doesn't help a lot, you know). So, do you have any clues / ideas about what is happening to my t220hd (yes, it had surpassed the warranty like 2 years ago so it will be no problem replacing a component)? Maybe is it the circuits of the matrix of the LCD and I have to order a LCD replacement (which maybe is not worth)?
Thanks a lot
Javier
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