HP Compaq Presario SR2010NX PC Desktop "tower rear lights meaning" Questions

tower If it is one the front near the power button, it indicates power supply is failing...and other indicator is the motherboard is failing. Now if it is in the rear where the ethernet cable hooks up

...rear of the tower? Could be a number of things wrong with this tower. -If the computer stays at a black screen with a white cursor, it means it's missing system files and the operating system cannot ...