Various issues with the chassis and cabling can cause no boot situations.
- Check for foreign objects inside the chassis, such as screws, that can ground the desktop.
- Correctly attach the desktop board to the chassis base with the spacers/stand-offs. Make sure not to tighten the screws too much.
- Check that the cables connecting the chassis front panel to the desktop board are plugged in properly to the Front Panel Header.
- Make sure the drive ribbon cables inside the computer are attached correctly and securely.
- For IDE drives, check the orientation of pin 1 of the hard drive cable. A cable connected backwards can cause boot failure.