Greetings fellow iusers!

I have a problem that seems to be getting the best of me, i'm just clueless... My 4S fell into sea water and isn't feeling very well, so my friend gave me his iPhone 4 so i can use it. It is a jailbroken iphone 4 on ios 5.0.1 i believe. He has tried installing something on cydia and iphone fell into a respring loop... I have vigorously searched for solution, and i can't seem to be able to find one. The thing is, i can't get it into dfu mode (i know how to do it, done it hundreds of times, so it's not my technique)... There isn't enough time, because the respring occurs as soon as the home screen appears, and that obviously resets the timer counting the time i'm pressing on to the buttons. I have tried doing a hard reset and then holding home+power until dfu while it boots up, but nothing happens. I can get it to recovery mode, but that doesn't help - my computer (or other computers) won't recognize it...at all...not even a bad driver message appears. Phone can charge, both on pc and power outlet, but that just boots it up and phone resprings until the battery goes dead. Any help will be greatly appreciated, because this problem seems to be just too much for me...

Thank you in advance!