New builds that act whacko need to be restarted from square zero. Disassemble the entire unit, double check the standoff locations and those needed for grounding on the MOBO. Only use the bare minimum components to acheive first the video BIOS, then the CPU system BIOS, memory count and a single beep(if a speaker is connected or optioned) and keyboard lite flash and a search for bootable device. Enter into BIOS and insure all is well before adding more memory, CD/DVD drive, hard drives one at a time. If the video is a plugin card, that may be the fault as it can be ground sensitive as in not good enough under higher currents and dropping out. Onboard video can suffer the same fault and standoffs can be so important in two ways. They can provide a ground where needed for the power supply and are usually closer to the higher current drawing devices and should have soldered traces around the mounting hole. The opposite can also happen, metal standoffs too close to traces can be subject to thermal growth of the PCB and shorting out of nearby traces. Serious investigation into proper placement is usually in a MOBO spec sheet and should be followed to the letter. I use nylon standoffs and screws, only providing a ground where needed with a simple copper strap around the standoff to the chassis. The failure to start first time every time is from an inadequate ground and the needed voltage not being drawn through the circuit to start properly the first time.
Edited by mjd420nova, 14 April 2015 - 04:54 PM.