Are there any methods to copy some files from my dead mbp to an external drive?
BTW, it would be helpful in threads like this if you included what Mac that you are having a problem with. I had to look at your past post history to find out that you have a 17" 2011 MBP which is why I posted the link in my first post. I still do not know for sure if that is the Mac that you are having a problem with.
Unfortunately all options require access to another Mac since your current one does not work.
A few possible options would be (in order of most likely to work);
1) Check for your files on your backup connected to another Mac.
2) Remove the internal hard drive, place it in an external enclosure, & connect it to another Mac.
3) Use Target disk mode using another Mac. I'm not sure if this will work with the state of your problem Mac.