!!
critical HP
Error Code Red LED flashes 4 times
Power failure due to overloaded power supply.
? What Causes This
Wrong voltage selector setting, faulty or mismatched external power supply.
✓ How to Fix It
- Check power cable connections on system board.
- Test each attached device for malfunctions via removal and re-insertion.
- Replace power supply if necessary; replace system board as last resort.
Source: page 148 of the official manual
From the manual
This error code appears in:
HP Compaq Pro 6300 SF Desktop