Dell Latitude E6400 Windows 7 docking problems?

My History of this problem.

1. I reported to Dell that the laptop was overheating. The computer was working properly in my current Docking station when not overheating. I was getting 100% CPU randomly but not all the time.
2. They sent a technician out to replace the mother board and heat sink because they thought that the heat sync may have dislodged from the mother board.
3. After replacement of the mother board, the laptop is no longer over heating but it will not connect to my docking station without the CPU going to 100% (Unusable). The monitors are also not detected.
4. The technician stated that this was a problem with my docking station. I stated that the docking station was working properly before he replaced the mother board but he is the professional
5. Dell have forwarded me a new docking station and it is acting the same way it was with my current docking station. When I dock my laptop the CPU pins to 100%


Even if my laptop is started and then I connect it to the docking station to the laptop CPU goes to 100% after 3-5 seconds and is unresponsive. Once I disconnect form the docking station, the CPU comes back down to 1-5% and works well.



I still have a open call with dell and have a tech comping out on Tuesday. (4 days from now.)



I do notice that when I start the laptop with it docked and go into the Bios. The current clock speed shows 666mhz!!



If I disconnect from the docking station and then reboot into the bios I see that the system clock is running full speed. Wierd stuff. I will report back to see what Dell concludes. Good luck.

When I don't use the docking station it's fine. If I plug in an external monitor using the VGA port it's fine. But when I use the docking station I have to plug in my external monitor using the digital outputs. THAT's when the overheating starts. The GPU is pushed to the max when driving two monitors at high resolution.

My understanding is it's a problem with the GPU. It's just too much. I updated the BIOS - no help. This happens in Win7, WinXP and Ubuntu Linux.

I don't see any solutions other than a DIFFERENT laptop.

I have the exact same issue. Just yesterday I changed my video from 32 bit to 16 bit and the problem has not occurred since. I am not sure about it overheating, every utility I have used showed that it was not getting hot. Since I do not do much with the graphics side of things 16 bit video is just fine with me.

@bimplebean et al

Apologies for bumping a very old thread but it's highly relevant to the problems I'm experiencing.

I've recently started a new job and been given a Dell E6400 laptop to work with. Yes, it's pretty old by tech standards but to be fair it would be fine if it didn't have this downclocking problem.

My scenario is as follows. It runs fine, all the time, when undocked. Dock it in a Dell E Port or E Port II port replicator (docking station) and it's still fine as long as you don't plug the power into the port replicator (although that's a bit pointless as it means I can't use the port replicator). Plug the power into the port replicator and the laptop is *immediately* downclocked to what I presume is its lowest clock speed, 800MHz. CPU core temperatures are fine before and during the downclocking - it does this even with them as low as ~40c.

What I've tried...
1. Update BIOS to latest (A34). No difference.
2. Replaced CPU heatsink thermal paste with top quality thermal pad. Temps are significantly lower but... No difference.
3. Thoroughly cleaned fan and exhaust grille. No difference.
4. Tried multiple difference port replicators and power supplies. No difference.

I can't believe it's overheating as it happens immediately (and recovers immediately if power is removed). Perhaps it *thinks* it's overheating and needs to downclock, but why that would happen simply with power being applied to the port replicator, I have no idea.

Was this problem ever, genuinely, solved?