Monitor Repair

[sdanks]

I have 3 KDS monitors that all have developed the same problem. After about 30 seconds or so, they just go blank. I have researched this and it seems that lots of the boards say to replace all the electrolytic caps and that should fix it. So I ordered 3 kits from an online LCD Repair place and they came with the wrong parts. So I have ordered some capacitors from Mouser.com and they should be in tomorrow. I will try to keep everyone updated on the progress. I don't have an oscilloscope or schematics to work on the board so I am shotgunning it. The caps don't look bulged or corroded so I may be barking up the wrong tree. But I bought caps for the 2 monitors for about $9 for each monitor with shipping. If it fixed them then I am happy. The third one is the one I have been replacing parts one at a time. It works now, but I will have to leave it on for a while to see if it is really fixed or not. I really don't know what fixed it since it was going back off after it powered up and said "No Input". I finally decided to hook up a computer and it works, or appears to. I would think with no input you could still bring up the menus, but I guess not.

Anyone else been fixing monitors for a while?
Just curious.

[randy]

Been doing it all my life.. well for 48 years.

Without a schematic an ESR meter is priceless and inexpensive. It will usually check a cap in circuit.

[sdanks]

Thanks. I hate spending another 150 bucks for another monitor if $9 in caps fixes it.

One question. If the cclfs are not plugged in can the monitor still work or will that turn off the circuitry if they dont see a load there. I would guess if that still works, I could unplug the ccfls to make sure they are not arcing or causing the monitor circuitry into a safety shutdown scenario. Then use a flashlight to shine on the screen to see if the image is there. The power light comes on blue and after displaying no input, it turns yellow and the screen goes blank. I figure I can change out the caps anyway and see if that fixes it.

[randy]

Thanks. I hate spending another 150 bucks for another monitor if $9 in caps fixes it.

One question. If the cclfs are not plugged in can the monitor still work or will that turn off the circuitry if they dont see a load there. I would guess if that still works, I could unplug the ccfls to make sure they are not arcing or causing the monitor circuitry into a safety shutdown scenario. Then use a flashlight to shine on the screen to see if the image is there. The power light comes on blue and after displaying no input, it turns yellow and the screen goes blank. I figure I can change out the caps anyway and see if that fixes it.

In most you can, I have seen some where the inverter will not run without a load and can stop the monitor from coming up. In most it will run without the CCFLs connected and if you look carefully you can sometimes see very faint images.