Well, you could try leaving the CMOS battery out for 2 hours (with the AC adapter unplugged of course), this will clear it, which may help. Also, while it could be a motherboard component level failure, it could also be something wrong with the AC adapter (maybe it's not providing enough voltage, or current) so I'd suggest you rule that out first. Do you have another one you could try (with the same voltage, equal or higher amps, and the same sized DC jack?? Do you have a bench 30V power supply?