Neither New Nor Old Memory Working after an Attempted Install

If your old memory is no longer functioning after an unsuccesful install attempt, a likely cause of both issues is one of the following factors:

Improper Installation: Double-check your install steps (install guides can be found here), paying special attention to ensure you are using enough force to seat your parts and using the appropriate slots for installation, to be certain the modules aren't simply incorrectly installed.
Power: Be sure you've firmly reconnected power cables disconnected from your system when you began, both at the outlet and into the computer itself.
Loose Internal Cables: Sometimes the force used when seating memory can flex your motherboard in such a way as to loosen your system's internal cables. Be sure all internal cables, especially between your internal power supply unit and motherboard, are still firmly connected.
BIOS Conflict: Sometimes it is necessary to clear BIOS settings to solve boot related issues. Your BIOS/UEFI may have a soft reset available for this process, or a jumper which can be used in place of the below steps.

Otherwise, manually clear the BIOS/CMOS, install the memory, and follow the instructions below:

Turn off the system and unplug it
Remove case cover/panels
After the system is open touch an exposed/bare metal part of the computer to ground yourself
Looking at the motherboard you should see a small silver circular battery (like a watch battery). The battery will be held in place by a plastic holder
Remove the battery from the motherboard. This is usually done by gently pressing the metal clip on the plastic holder. The battery should pop up/out on its own
After the battery has been removed please leave the computer sitting like that for around 15 minutes
After 15 minutes replace the battery and the cover/panels
Reconnect all cables and power up the computer

If the steps above don't solve the issue, please contact us for further support.