Dell monitor 2209WAF problem

[N2IXK]

CCFL Lamps can do that toward end of life. Check regulation/ripple on the power supply feeding the inverter.

[rlovison]

Originally Posted by N2IXK

CCFL Lamps can do that toward end of life. Check regulation/ripple on the power supply feeding the inverter.

Will do, thanks for the tip. Will one or more failing CCFL lamps cause the whole array to dim?

[rlovison]

At the connection feeding the inverter, the ripple looks to be a fraction of a volt (a Fluke 77 gives me .125V though at the scope it looks more like .5V peak to peak) at about 2.9Mhz with a dc output of 24.06V.

Now, about one hour later, the ripple is more like .05V on the Fluke and looks reduced on the scope as well. The screen just did it's dimming thing and the 24.06V reading stayed the same during the dimming as well as the ripple voltage. Within less than a minute, it popped to full brightness again.

When the monitor dims, I don't see a color shift or pinkish glow, just a reduction in brightness.