THE DEAD PC (see that on google) is where we just don't know what's dead. It could be simple as a dead CMOS battery so I get out the Volt meter (if you work on PCs you need one) to measure the battery, My criteria for the common CR2032 is over 3.00 Volts. 3.00 and lower are replaced.

Now that it's a basic check we turn it on and check all the PSU legs. All must be within say 10% of their expected value or the PSU is suspect.

Now that's done we unplug everything that is optional. This varies with the PC but the i7 has graphics so we don't need the GPU. The drives are removed, we reduce the RAM to one stick and unplug ALL motherboard connections except power. To power up we use the pen tip as we learned on google of "THE DEAD PC." If that doesn't give video then we are looking at the possible bad parts.

If we are this far into the PC the next stop is to remove the case. The PSU, motherboard is set on cardboard and we try one last time. At this point it's only what parts are left.