Lenovo ThinkPad T400 turns off after connecting monitor via VGA

I am having the Lenovo ThinkPad T400 and that is showing me some problem with that. Actually this shuts down immediately while I plug I the monitor (Dell WA2209). If I shut down PC and after that try to turn it on as the same time as the computer through the monitor plugged in, the computer shuts down almost immediately subsequent to I press the power button. In every case, I have to unplug the computer and take away the battery before I can attempt turning the computer on once more. I have installed the newest power manager. On the odd incident, I am able to plug in my monitor devoid of the computer shutting down. This happens once using incorporated and discrete graphics. It worked for approximately one year just fine and newly started doing this. Do you have some idea for that? Thank you so much in advance.

I think that you will have to update the video driver that you are having and along with this, try to update the BIOS as well. This can resolve the problem that you are facing. There are some of the cases where updating the driver and BIOS resolves the problem and I hope that it will do the same for you.

There might be some problem with the VGA cable that you are having. You can try to make use of some different VGA cable.

This can be problem of the overheating. I am not saying that this is the only reason for this but it can be considered as one of the possible reasons for this. If you want then you can try to use the Prime95 program and check what it can do for this. I was having somewhat similar problem earlier but with some other laptop and I used the same and this solves the problem for me. Therefore, I am recommending you the same and hope that you will be out of the problem after this.

If you wish to get the exact solution for this then you can call the Lenovo support and ask them for the same. They will tell you that exactly what you have to do and what is the reason for this problem. This will be the best thing to do get the most precise solution for this.

You can take the palmrest and keyboard and then clean out the fan vanes through the cotton buds. If you are having the vacuum cleaner then you can hold the fan vanes and after clean the dusts from the heat exhaust as of the left hand side of the laptop. You can try with some other ports available on that and see if that can help you to you. Thank you and good luck with that.

Just search for the HWMonitor and take a look to the Thinkpad temperatures. You can as well download TPFanControl the chosen option to organize our Thinkpad's fan values. Either the T400 is overheating otherwise there is something incorrect through the motherboard. You should examine the temperatures first, and after that see from there what could be mistaken. Have you attempted with running the laptop on just the battery. If you accomplish this test ensure the CPU mode is in the saving mode. By this method, you could decide if the laptop is overheating since CPU will underclock and work at the lowly voltage and the frequency therefore the CPU would not seem to be problem with that. You should notice that usual CPU temps on a Thinkpad must be on the 40's range. At load time you must see around 55-65C. T400 are not recognized to encompass problems through overheating, if laptop is overheating put this for replacement.

Thank you so much to all for the replies. Changing the VGA cable resolves my problem. I recommend to all, if having the same problem then do try to do the same.