Inspiron 9400/ATI x1400/video flicker on external dual lcds

Have external LCD flickering on Inspiron 9400, Duo, x1400.  Me thinks this is overload related.  Have one external screen DVI 1600x1200.  Same screen (actually two different models depending where I am) worked fine with Inspiron 9200.  Still investigating.  My problem starts when the machine is running for some time, specifically in afternoon when warmer.  Remove all windows, flickering goes away.  So overload is a bit related to what kind of signal it gets.  Seem very "heat" related.  Don't know yet.  Disappointing, wastes time.  I guess they're pushing the limit.

Here's my experience a day later:

Go to ATI Catalyst Control Center, Advanced..., Digital Panel Properties, Attributes.  There are two options in DVI Settings.  Try them both in different settings.  Remember to hit Apply.  To be sure, restart too.

Mine seems to be working better now with ON Reduce DVI frequency (thought I was down at 60 already, needed it anyway for perfect results, go figure) and OFF Alternate DVI operational (hint from 2005 review of Samsung 243T by Sean Carruther).

Please let us know whether that works for you too.

Too late at night / early in the day to say whether this fix is for good, but seems so far.

For the record, it seems mine was preset OFF Reduce DVI frequency, ON Alternate DVI operational.

Also I have installed and tweaked freeware tool Dell Inspiron fan control utility from diefer.de.  Do that at your own risk.  Takes time to figure, and it is important to do it in a quiet room at first to listen to what's happening with the fans.  Don't use sensor for control, let it do that at simpler Slow and Fast.  Told it to cool all parts, including GPU.  My GPU is now below 50 Celsius, while before it would go over 60 Celsius.

Sorry to hear that.  I'm still fine with mine, and I've left it running.

I'm using I8kfanGUI (3.0 beta 5) from http://www.diefer.de/i8kfan/.  It is free to use.  I have taken the time to figure it out, configure it so it cools the GPU (triggers when it gets hot), not just the CPU.  Using slow/fast mode, not the 0 to 64, to make it work with this Inspiron 9400.  I can describe settings if you can't figure it.  Make sure you don't misconfigure it to fans off and kill your machine.

The ATI X1400 GPU (per I8kfanGUI) seems to be getting hot when running an external screen, compared to other parts in the machine, compared to another Inspiron I have next to it for now.

No external fan could be that good at cooling inside the machine as the fans inside the machine, me thinks.  With sensors to trigger it.  Neat.

On the other hand, one could say you're just doing "too much" with the two external screens.

Also, today I am in an office that is air conditioned, and the machine is much cooler when idling (per I8kfanGUI).

I8kfanGUI isn't perfect, but it is very useful.  The guy writing it just couldn't keep track of all models and undocumented features, for free.  One can donate by PayPal.

You shouldn't add a physical fan.  You could/should try running the existing internal fans more often, after carefully figuring out http://www.diefer.de/i8kfan/

I am not sure yet what to do about it.  My machine seems to be working now.  Had a hint of a minimal flicker come back after a few days, so I further reduced the temperature setting for the GPU by another 5 Celsius (45 now).  Flicker is gone.  But doesn't feel right, I am in a seriously air-conditioned (almost refrigerated) office now, and even here fan now never stops.  Will it get worse back at my own office?  Will this machine fail next summer?

This isn't good.  Seems like ATI has a quality or heat or something problem.  I'm not saying it is easy making that stuff.  But is seems they put in more than they can make reliable.  Would be nice to know whether let's say 3% or 1% of users have that problem and Dell could just swap our cards for another X1400?  Or is the whole series unreliable?

I have usage patterns that are similar to Maaximuus. Seems we do similar work. I find that my screens sometimes blink in quick sequence but more often independently. I will see one flash out of the corner of my eye while looking at the other. I would say that this happens on average twice per hour.

It seems to happen less often in my home office than at my client's site. This may lend some support to the heat theory, because at home my 9400 sits on a perforated steel monitor stand, where at the client's, it sits on an old HP docking station that has a rubber base and wraps around the front of the unit. I would have to say that it would run hotter at that location.

Since I seldom use the battery, I may try removing it and see if the heat reduction of no charging has any effect on the problem.

Does anyone have an open case number on this with Dell support?