1. Yes, try a new CMOS battery. From 1 to 5 bucks. Worth a try.
2. Google BAD CAPS then inspect your machine. The symptoms are correct.
I have a 3 year old Compaq Presario SR2020NX that recently developed a problem starting up. When I hit the power switch, the fans switch on (and remain on) but there is no boot screen. I've tried unpluging the unit, holding the power button 5 seconds to reset the power. That ends up doing nothing but the unit does boot and start regular after several minutes of retrying it. I have made a good inside cleanup inside to remove any dust that might cause problems. It is just tricky to figure why the fans would keep going on non stop with no boot unless it is related to the power supply and/or battery. However, I do find that if I unplug the computer totally and wait for a few hours, it will start up ok. Please advise