kbs1
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Aug 20, 2012, 3:47 PM
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iiyama ProLite X486S backlight not working
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Hello, I have this 19 inch PC monitor IIYAMA ProLite X846S whose back light is not working. I can see the picture when I shine a flashlight on it. It was working and then one day poof - nothing. I did a lot of short circuit troubleshooting on the inverter board only to find out nothing I checked is shorted - that includes diodes, mosfets, other transistors, random resistors and so on. Now I know this is not a television but a PC monitor, but this forum seems to be most vivid and I feel there might be some good help around here. In the time the monitor is broken I have already bought a new one, but having two monitors seems like a really good idea, so I'd like to repair it. Now I have bought / did previously have this equipment: 1) a cheapo DMM (ohms, amps, voltage, diodes, continutiy) 2) 20MHZ oscilloscope 3) a good LCR meter (to test capacitors) 4) soldering iron Now the backlight does not come on at all, never. I have even measured voltage coming directly to CCFLs when the monitor is ON (even accepting the fact that this could ruin my cheapo multimeter / whole monitor) and there are 0 volts AC and 0 volts DC measuring any possible combination of the 4 input pins. So measuring that I have (possibly) ruled out the possibility of bad CCFLs, which leaves the the fault to be in one place - the power supply. The board is visually undamaged, unburnt, and I can post detailed pictures, just let me know. I also have similar PSU diagrams and datasheets. The PSU part number is 715G1236-3-AS ver:A Now, any ideas where to probe? I have only a very basic knowledge of electronics. Thanks :)
(This post was edited by kbs1 on Aug 20, 2012, 3:48 PM)
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