I picked up 2 free lcd monitiors from work. One works and the other doesnt. The screen turns on and makes a hissing sound. It works for 30 seconds then shuts off. Would the hissing be from the inverter board or the CCFL lamp. Would a capacitor Kit fix this? I already have a working LCD that is the exact same model. But i dont want to tear apart a perfectly good monitior to swap parts.
If the inverter for the cfl is bad, you can still see the image with a flashlight. If you can't see an image it's the mainboard. It's more than likely a capacitor issue. Be careful CFL inverters can kill you.
yea i know about the killing you part lol. Ive worked on one before. The screen is useable for about 30 seconds and shuts off. It flickers the entire time while on. I remeber reading something about how if one cfl is bad it will cause the monitor to turn off. Does that sound right?
Capacitors are a bitch. I do the cap replacement for the people who refuse to let go of their iMac G5 (the ones with the 30% failure rate due to caps). But I'm not sure about one CFL being dead. It might be true if they are wired like those old christmas lights. One is out they're all out. and I can see why- if you've got bad caps and one CFL goes, then it's not going to want to run the rest as it might cause erratic bulb behaviour (exploding?). But I wouldn't suspect the bulb itself to be dead. Normally, in my experience (so I could be wrong) but it sounds more like an inverter issue, as per ASSEMbler. Open it up, be careful and check the tops of the capacitors to see if any are leaking. Does it smell like burning tires? when that smell, combined with a hissing noise means that your caps are dead, 100%. EDIT- thought a little more. If you can't see anything when shining a flashlight on it, check the monitors power supply (should be internal) Those have capacitors as well, and are prone to damage. It could be that that is at fault, sending out a wonky power stream.
yea 2 of the caps look a little bubbled out. I got a cap kit for 12 bucks on ebay. I really want to get this one working so i can run dual monitors because it's the exact same as my current monitor.
A video re: hissing in monitors watch 3:07 : https://www.youtube.com/watch?v=3YDjVxNpKH8&feature=relmfu This was an arching backlight. I had one similar to it, I havent watched the rest of the video in a while, but i think the screen was partially yellowed
Thanks for the help guys. Based on the video I don't think i have an arching backlight. Mines like a hum/hiss, It wasn't crackling like the one in the video.
Did you try googling repair and the monitor's model? There may have been a few posts or blog somewhere of monitor's diagnosis, attempted repair, and such. I got a 24" Soyo monitor for free because it was just dead. Based on the search, the common problem were bad caps in the power supply. $15 later it's working. Very cheap or free LCD are very nice if they are working or can be easily fixed.
I would suggest not undertaking such a project without a sound knowledge in electronics, particlarly LCD television theory / repair. If you have to ask, and you really want to do it yourself, get yourself on a television repair course.
Got it working thanks for the help guys. 13 bucks got me another matching 19 inch monitior. Only problem is the repaired monitor doesnt look as good as the other. Whites and all colors are not as white or colorful. I have reset both to factory settings and they still look different. I switched signal cables and same problem. Could it be that the repaired monitor just has more hours on it. I got it from a car dealership so im sure it was left on 24/7.
The CFCL would be weak for sure then, and there would be significant bleeding of light. As long as it works, then it is fine.
