One Beep :DRAM refresh failure
This may be due to
- Bad memory chips
- A bad DMA Chip
- Bad memory addressing chips on the motherboard

Two Beeps :Parity error or Parity Circuit failure
-Your memory may not be seated properly on the mother board.-Unplug and plug it properly

Three Beeps :Bad memory or bad mother board

Four beeps :Timer failure in the RAM.

Five Beeps :CPU chip may be dead

Six Beeps :Keyboard controller may have failed

Seven beeps :CPU is dead. Retry the connections and test.
-Replace the whole motherboard.

Eight Beeps :Video card is missing or Bad.

Nine Beeps :Damaged ROM BIOS.
-BIOS chip has to be replaced if it persists.

Ten Beeps :CMOS shutdown.
-Replace CMOS memory and associated chips.

Eleven Beeps :Cache memory test has failed.
-To enable cache memory try CTRL+ALT+SHIFT++.

One long Beep and Three short Beeps:Memory failure

One long Beep and Eight short Beeps :Video card failure.
-Try to install video card in another slot.

No Beeps :Check Power supply
-Check mother board connections
-Remove all cards except video card and check for system power up
-Insert all cards one at a time and check their operation.
-If system hangs on the installation of a particular card, then it is the cause for the problem and replace it with another of that type and check.