Yet Another DS Problem (stuck on first boot)


Hello, I experienced almost every possible problem with DS and DSLite but this one was new to me.
Basically I bought some DS Phat "junk" and see if I could restore some of them. One was succesful, meanwhile other 2 PCBs have a problem: when they start up they ask you name, date, time, birthday and so on, then they ask you to reboot the console. At that point, you should be able to start up the console and play after the "safety" screen. What happens is I don't get the Safety screen and I get again the first boot, asking me the same stuff as before, kinda like I removed the battery when it asked me to reboot the system.
So yea I can't start the consoles because they stuck on the first boot forever and fail to memorize settings. I already tried changing battery, checked F1 and F2, and now I'm totally clueless. It's also a weird problem so I have no idea where to watch to find the problem. Are the PCBs gone? What can I do?

Thanks in advice.