Acer AcerAltos 21000 System Manual page 77

VRM LED
There is one LED indicator for each VRM module. Before system
power-on, an LED would light up (green) if a VRM is required for the
processor or the L2 cache. If you see a red light after power-on, then
it means that the VRM is bad and that it needs to be replaced.
To install a VRM:
1. Find an empty VRM socket and flip the lever back.
2. Carefully insert a VRM into the socket. This process will
automatically lock the VRM in place.
To remove a VRM:
1. Push down both the locking mechanisms.
2. Take out the VRM.
System Boards 3-13