Issue
- A memory failure message in AMT for a DPU or SCU Controller
- When presenting a valid key card to a door reader, the LED on the SCU turns Green but the relay does not fire. The relay can be controlled manually via the workstation in some instances.
Environment
I/NET Door Controllers
Cause
This memory failure message is generated when the DPUs or SCUs do not have sufficient voltage supplied to the board. This can either be a bad 24 VAC Transformer or from a gel cell battery.
In most cases if there is a battery backup of the controller, the gel cell battery has had a deep discharge applied to it. The charging circuit on the controller cannot recover the battery to its proper charge value. Even if there is a good voltage value from the transformer, the charging circuit load is so great, it restricts the main board of the necessary voltage to keep the RAM alive.
Resolution
- Remove the two wires from the controller that go to the gel cell battery.
- Get a replacement battery as soon as possible.