PC Will not boot!

Hi @rocketpyro ,

Did you try a “Power reset” to reset the BIOS to default values and check if it starts OK?

To do this, switch off the PC, remove the power cord from the outlet and also the RTC battery from the motherboard and press and hold the Power button for 30 seconds. Reinsert the RTC battery, connect and switch on the power and try to start the PC.

Since you have tried a new motherboard, (was it a known working motherboard?), a new PSU, a new RTC battery and a new CPU, have you tried the new (or the original) motherboard in lieu of the one you tested the RAM and HDD on to see if it worked there? At least to see if it starts and passes POST and you can get into BIOS anyway.

If the replacement motherboard (or the original) now doesn't work elsewhere either, (your question indicates that you changed the motherboard before changing the PSU), I'm wondering if the old PSU may have somehow damaged the motherboard and subsequently the 2nd motherboard as well or may have only hopefully corrupted the BIOS somehow in both motherboards.

Have you tested the old PSU to make sure that it is OK re the voltages supplied by it? Use the paperclip test and check that all the relevant voltages are within specs.