Why won't my camcorder turn on?
My device won't power up even though the switch is in the "on" position.
There might be two reasons for this issue. Initially, the battery might be dead. In which case, you must replace it with a new one or charge it up in order to resume using the device. Secondly, the hard drive might be broken. This is a more serious issue and it requires the hard drive to be replaced with a new one.
For more information refer to Sony Handycam DCR-SR42 Troubleshooting Guide