Preventive Maintenance for Studio Engines

[Andrew_KOOP]

Hello,

We wanted to pass on something that we observed which might be helpful to others and may be something to consider as part of whatever preventive maintenance tasks you do around your station.

We have an older (with fans) studio engine. This engine has a Asus N4L motherboard. This motherboard relies on a lithium coin cell battery to maintain it's bios settings when power is removed. Many newer motherboards store their settings in nonvolative memory, but this board is not among them.

When this battery dies, it will not produce any symptoms on as long as the unit is powered up. When power is removed, however, the unit will fail to start again. Specifically, the bios setting that tells the unit to start up when power is applied will be gone. ATX power supplies require a signal from the motherboard to start. As a result, the symptom is that the unit is dead, the power supply fan fails to spin up, and there might be a single LED lit on the motherboard from the few ATX power supply lines that are live when the power supply is in standby.

To prevent this, it may be worth proactively replacing the batteries every couple of years. You can replace then while the unit is on AC power to avoid the loss of the bios when removing the battery.

In our case, we recovered the unit by locating the pins on the motherboard header where the "power" button would normally connect. We shorted those pins and the power supply started and the unit came up normally. Then we reprogrammed the bios and made a trip to the grocery store to get another coin cell battery.

Somewhat ironically, we made this discovery when we were trying to install a new engine to replace a previously RMA'd unit. We decided to move some things around in the rack, which led us to momentarily unplug our fanned unit. Perhaps this experience will prevent a similar experience for someone else.

-A