Clamshell mode help

I have a 2007 macbook pro running Snow Leopard.

The screen is not working so I hooked it up in clamshell mode to my toshiba monitor. Everything was working as expected. However, when I changed the resolution I started getting an "unreadable source" message from the monitor. I tried resetting the NVRAM but it didn't help. I am still getting the "unreadable source" message.

Any suggestions?

The problem you're running into is that you've got to get the MBP back to the native resolution of the Toshiba monitor. You can try resetting the SMC on the MBP to see if that will work: LINK

If that doesn't work, you'll need another Mac with a firewire port. Hook your MBP to the other Mac and then boot your MBP from the other Mac. You should then be able to go into display preferences and reset the native resolution for the Toshiba.