My Photosmart 7520 printer comes on for about 4 seconds then shuts off

You can try these troubleshooting steps for when your printer doesn't turn on:

There are a few possible reasons why your Photosmart 7520 printer may be shutting off after only 4 seconds:

1. Power supply: If the power adapter light is turning off, it could indicate a problem with the power supply. Try unplugging the power adapter from both the printer and the wall outlet, then plug it back in and try turning the printer on again. If the problem persists, you may need to replace the power adapter.
2. Overheating: If the printer is overheating, it may shut off as a safety feature to prevent damage. Make sure the printer is not in direct sunlight or near a heat source, and that it has adequate ventilation. You may also want to try turning the printer off and letting it cool down for a while before trying again.
3. Hardware failure: If neither of the above solutions work, it's possible that there is a hardware problem with the printer. This could be caused by a variety of factors, such as a faulty power button or a malfunctioning circuit board. In this case, you may need to take the printer to a repair shop or contact the manufacturer for support.