Desire getting tired - can it be refreshed with firmware upgrades?

[Morat]

Well,
my Desire is now officially my "old phone" after my SGSII arrived - but I still love it despite some issues that had crept in towards the end of it's contract period.
Mainly, the bluetooth doesn't seem to hold a connection with my car radio anymore. (The Samsung works perfectly). Also, when using Navigation it overheats and shuts down.

The phone is an original OLED screen version (Orange Branded) so I'd like to get it back up and running if possible, even if I end up giving it to a friend - but I would also like to try rooting and different ROMs now that it doesn't really matter if it gets bricked.

Could you point me to some places to look for info?
thanks
Morat

 

[Morat]

This is probably kinda useless without my current versions

HBoot 0.93.0001
Microp-031d
Touch Panel-SYNT0101
Radio-5.10.85.30

 

[Hadron]

Go to the all things root subforum and read the guides and FAQs (in a sticky post, which is also the red link in my sig).

Once you've done that people there will be happy to answer any remaining questions.