Warranty reasons - Problem with Htc touch pro

[rickardo8]

Hi people...(sorry for some errors in the english)(i'm from portugal)
I have a Htc touch pro with some problems...(the space and other letters only work with very pressure and the phone at times restart alone)

I have buy the phone in miau.pt from other person and at this time i have warranty at least 1year and 3 months...

I have search in this forum but I don't have found a similar case...

I have send the phone for warranty, thinking that the phone was the original software...
The guys said that the phone don't have the original software, and not give any warranty...

I want try to put the phone original and send other time to warranty...

Do you help me with this? I don't have much experience but I have to learn and try...
I don't now what the guy have modified...
I have read that is possible to modify spl,radio and rom...
I only want the phone original to win green light in the warranty...

What is the best way to know what is the original rom?

Please people, help me with this...

Best Regards
Ricardo Afonso