I don't like when users here makes confusion with their's issues and inquinate some other's post, let's try to remain on the O.P. sympthoms. As always is not bad to take out the PSU and test it with dummy loads, even if i don't think it is the problem.. also one can stimolate an heat related behavior by sourcing some hot hair to the boards, starting from the t-con, ending on main b'd, triyng to locate always more precisely the area of failure. No one has said if when screen goes blank you see a backlight lit. It is possible that an unconsistent short on a mosfet or ic on tcon or main let go in to protection the psu shutting down also backlight.
It was quite a shocker if you know what I mean ;P I don't think I have the test tools that you all do so I'm going to take a different approach and swap out the parts from another monitor until I find out which one is broken. Then I will try to find out what is broken on that part.
One thing I noticed is that a different unit of the same version of my monitor the brightness is so much more powerful. It is hard to see the screen on the monitor that is faulty with the brightness all the way up while it is working. The other unit is easy to see the screen with the brightness at 50%.
90% is a bad.. or are.. ccfl lamp/s, sorry, difficult adventure for you.. it's strange 'cause as the initial of the thread the OP says that with brightness at minimum it lasted longer, but with a faulty lamp it lasts longer with higher brightness, 'cause the higher voltage wins the damaged/burnt electrodes resistance..
After a series of swap and replace actions I found the problem to be what I believe is the power supply. Does it make sense to try to figure out what is broken on the power supply or buy a new one? I swapped the power supply and the power conditioner to get the monitor back to life.
"power conditioner" is a term that i'm unable to translate, anyway that is a mains input filter...
"It has lasted at least a dozen hours."
what do you mean? At which one do you refer?
It's very a strange behaviour, ususally a bad psu board doesn't work for minutes or hours and after it stop.. apart maybe for bad solder joints, but on switching psu without high voltage transformers i've never heard.. only a thing makes me supect now, since you talk about that "power conditioner" board, on it there is an NTC, it is the 2 legs green pastil, try to measure it's resistance by cold, then measure it in the meantime you heat it with soldering iron, if you see that the resistance lowers to approx 0 ohm and it lasts, it's ok, if not is broken.
Replaced the power board and "power conditioner" using parts purchased on and everything is running smoothly for the past few days. Thank you all for the help!
Darran, is your monitor still running w/o issue? I too am experiencing the same problem and want to know whether to order the Dell U3011 Power board PS-2201-3-HF. Thanks!
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