Description/Explanation of Issue
Expression 3 and Insight 3 consoles were originally built with two super capacitors to provide power for the SRAM while the console is powered off. Later, the super capacitors were changed out with a battery. As such, the three primary reasons for a memory failure is either failing super capacitors, drained super capacitors, or a dead battery. Less frequently, memory problems may be due to failing SRAM.
To determine if your console uses super capacitors or a battery, open your console by turning the bottom two knobs on each side of your console and lifting the face panel. Find the CPU tray, which will be located in the center of the console, and unscrew the five screws holding the top of the tray. Inside will be the CPU board. The super capacitors or battery will be located near the edge of the CPU board closest to the front of the console. If your console has super capacitors, there will be two of them, slightly larger than a nickel in diameter. If your console has a battery, there will be a CR2477 battery in a coin cell holder.
The super capacitors will only remain charged for about four or five days before the SRAM will be erased due to low voltage. To help maintain show data, turn on the console every couple days for about a minute to keep the supercaps charged, or you can save your show data to a disk.
It is possible to retrofit an Expression 3 or Insight 3 console with a battery for easier serviceability. The battery kit is not available for non-ASC service technicians. As such, the console should be sent in to your preferred ETC dealer, or to ETC for repair.
If, after replacing the super capacitors, the console still loses show memory, it's likely the issue is the SRAM. There are eight SRAM chips located on the CPU board above the DRAM sockets. The SRAM is no longer available, but ETC does currently have a limited supply for repairs.