Can you help me to answer?
The Laptop model no: IBM T30
Power LED on and processor fan running but no display and no video output at VGA port and no beep sound at all.Its same condition after remove the CIMOS battery(2.8V).I have tried with other RAM, but still the same condition
There's really only one way to diagnose your kind of problem outside of an electronics laboratory and it doesn't matter if it's a laptop or desktop. You need to replace suspected problem components one at a time with known good components until the problem is located. This is usually not much of a problem for someone into building desktop boxes because spares are accumulated over time. Laptops are very different because the parts are unique to the model and spares are unavailable except to the manufacturer. I'm afraid you're probably going to have to weigh the cost of repairing an (probably) old laptop against replacing it with something current. Most people would replace it.