Problem using external monitor with MBP lid closed

Hi folks. I'm stumped, but I'm hoping someone here can help me. I have a 15" MBP, about 1 month old, and a 20" Dell widescreen monitor. I was able to figure out how to get it all hooked up so that I could use the Dell monitor as my main monitor and close the lid on the MBP (close lid, wait for it to fall asleep, wake it back up with external mouse or keyboard, and use from there).

A few days ago, I shut the MBP down in this mode as a precautionary measure during a lightning storm. Now I can't get the MBP to do that anymore. I turn on the MBP, let it get started up and stuff, then close the lid, wait for the MBP to fall asleep, move my mouse around, and a few different things happen:

1) instead of having the Dell monitor as the main monitor, it "wakes up" in extended display mode;

2) the MBP does wake up, but it wakes up only for about 1-2 seconds, then it falls back asleep again;

3) when I open up the MBP again to go back to using the laptop monitor, it is still "asleep" (i.e., the screen is totally dark) and I can't wake it up by pressing buttons or touching the trackpad. I basically have to power down by holding down the power button and then start all over again.

Anyone have any hints?? This is getting pretty frustrating.

Thanks.

 

I have opened the MBP again both connected and not connected to the monitor.

I think I have tried it. I have
- disconnected the MBP from the monitor,
- shut it down (because the display won't wake up anyway),
- restarted the MBP unconnected to the monitor,
- found the MBP screen to work fine,
- hooked it up to the monitor again,
- made sure it detected the displays,
- closed the lid,
- woke it up,

and STILL had the problem. I even tried it in mirror mode and extended display mode, in case for some reason that made a difference. No luck.

Is there any way to remove the display connection other than to simply unplug the monitor?

 

It worked, Stiphone! It must have been a really recent change. Like I said, less than a week ago, it was working with the "old" method, and then suddenly it wasn't. Weird.

And why did they come up with this new method of connecting an external monitor when the old one worked fine (and arguably better) than this one? It'll be a pain not to be able to just be somewhere else and then connect the monitor. I hope Apple figures that out and fixes it.

Anyway, thanks again!