Without knowing what point you are referring to.. Do you get to the boot screen? what point?
Be sure and always ground yourself by touching the power supply before handling the motherboard or other components to avoid electrostatic discharge. Use properly grounded outlet.
Non-conductive surface, such as a linoleum tabletop, cardboard or rubber mat.
Known good power supply.
Motherboard (Access/Enter Motherboard BIOS
and Troubleshooting BIOS Beep Codes
Video card (Troubleshooting a Video Adapter and Computer Monitor Flow Chart
RAM - one RAM stick (run memtest86
Keyboard - Not mandatory
Speaker - Hear beep codes
Power Supply -(Flowchart for ATX Power Supply Repair
best way is just try a known good power supply)
Remove everything from the case
Connect the components listed above, check all connections and be sure they are in their proper location and secure. If your motherboard has a small, square 4 pin power connector, your power supply will need one and it should be connected, it is required for proper operation.
If you have already tried the unit inside the case, reseat the RAM and video card a few times to clean up the contacts. This means pull the card out of the slot and put it back in, often 6 or 8 times are needed to clean off oxidation.
Locate the Power On pins on the motherboard and short them briefly with a small screwdriver, that should power up the computer. If everything is properly connected, in working order and contacts are clean, you should see a BIOS screen and hear one beep.
Now we know that it may be a Mounting issue and you should check each standoff that is not matching up with a hole int the motherboard
Or it may be one of the pieces of hardware we have not connected yet.
If you get no video or beep, switch off the power strip or unplug the power supply to shut down. Reseat video card and RAM. Sometimes this must be done several times, heavy oxidation can be difficult to clean up.
If you still get no beep or video after several tries and have reseated the RAM and video, further troubleshooting is necessary. I won't go into great detail here, but the things to check are:
Video card - try a different one.
RAM - try a different chip.
Motherboard - Have it tested by a reputable computer shop.
CPU - Have it tested by a reputable shop.
Power supply - A weak power supply can be difficult to sort out,Best way is to try a Known good PS to diagnose