Dell Motherboard Error LED

Sounds Like The Power Active Led That All Mb's Have

As raptorcigs says, most motherboards have an LED that indicates the status of the 5V standby power. If it is illuminated then that's a good thing.

On many circuit boards, components are identified by a letter and number.
Capacitors may be Cxxx, resistors may be Rxxx. You may be looking at the numbers for a capacitor and a resistor near the LED.

was to state memory wasn't running correctly have it all sorted now, thanks guys