At this point, the possible bad parts in order of cost are:
There is a simple part on the motherboard that should be checked with a voltmeter and that is the BIOS battery. If it's the usual CR2032, then anything below 2.8 or so Volts means you get another. At this point you've scoured the board for the jumpers that you've checked are all in the right places.
I always make sure the speaker is a good one. But my next move is CARDBOARD.
Remove the motherboard from the case since some builders may install too many METAL STANDOFFS and short out the backside of the motherboard. Place the four parts on the cardboard and set it up. Flip the AC on and use a spare jumper to power up the affair.
No BEEPS? IF you have a Voltmeter, you can see if the PSU has the correct voltage on each pin. If not, another PSU is obtained (always oversize the Watts!) and the test repeated. Then the motherboard and then the CPU/HSF.
yeah i have got it down to the CPU/HSF, Power Supply Unit(PSU), motherboard and the speaker, but still no beep from the speaker. dont know what to do next. thanks for the help.