Re: Will not boot, persistent yellow light, Vostros 220
If the power light is steady amber, there may be a power problem or an internal device malfunction.
Check for the Power supply light at the rear end of the tower. If the Power Supply Light Led is not light up, the power supply is defective.
Also, 1 beep indicates BIOS checksum failure and a possible motherboard failure.
I recommend you to disconnect the Power plug from the tower, press and hold the power button for few seconds and release to drain the flea power. Now try to restart the computer.
Refer the following link for more troubleshooting:
Please post back the results.