I know it's kinda late for Hrvoje to get an answer, but for anyone else who jas same problem, I found a solution.
As I allready wrote, I was right, the computer needs reset. I didn't find this online, but since I couldn't find anithing, I tryed to do it myself and it helped me, so I hope it will help any of you trying to find solution.
Here is what you need to do to reset the computer of WD105T:
1. Unplug the power cord from power suply.
2. Remove back lid as if you need to change the belt, unscreing 6 screws.
3. Facing the machine from its back, you'll find its computer at the bottom left inside in white plastic case.
4. Remove plastic cover from outside back witch you will notice to your left bottom betveen two screws holdin plastic computer case.
5. Unsrew those two scres from outside of machine so that plastic computer case is realised.
6. Notice that there is bunch of wires attached to plastic case with plastic holder.
7. No need to cut the holder, there is plastic pin that you can pull down to relise the wires.
8. Once you have the wires loos, gently take the computer out of the machine trying not to damage it, along with wires still attached to its mainboard.
9. No need to take the mainboard out of plastic case, even thou I did so. No need because there is no point to it, I did it trying to find a reset jumper witch does not exist.
10. Once you have computer out of the machine with wires still attached to mainboard, unlpug evry set of wires and the plug it back in one at the time.
11. One at the time so you dont mix them up.
12. Now put it all back inside the machine as it was and remember to attach the wires to computer case with a plastic holder. This is important so they dont go into the machines belt.
13. Also remember to put the outside plastic cover betveen those two scres holding computer case.
14. And that is it!!!
By unpluging every set of wires to the computer, you have computer reseted.
I hope this is helpful, and if it is, please contact me at zoran@audition-us.com I would really like to know if this has helped someone.
Also, please ignore my bad spelling of english since it is not my first language, most important is that you understud what I ment.
Thanks!
Bye!!!
Zoran, October 2006