Product

Machines affected

All output devices with MPE boards that are approximately eight years old or older.

Component

NVS battery on the MPE board.
NVS parameters are kept on a static RAM (SRAM) chip that loses information when the electrical power to the output device is turned off. To create non-volatile storage, we use a SmartSocket. The SmartSocket plugs into the MPE board, and the SRAM chip plugs into the SmartSocket. The SmartSocket monitors the electrical power to the device. When the power is turned off, the SmartSocket switches the SRAM chip from board power to battery power. According to the SmartSocket's datasheet, the NVS battery life is approximately ten years. The NVS battery cannot be replaced, so you must replace the entire MPE board.

Error

2200: NVS: low battery in NVS detected.
Note: This error message appears when the NVS battery voltage reaches about 2.0 V.

Symptoms

NVS data is lost or corrupted. Error code 2200 appears when the battery reaches about 2.0 V which generally occurs when the NVS battery is already too low to use.

Cause/Solution

Cause: If the NVS battery is lower than 4.5 V, the SRAM chip cannot retain data, and becomes corrupted.
Solution:

1. Back up the NVS data.
2. Turn off the device.
3. Perform a NVS dump and save a copy of the parameters to a text file.
4. Measure the battery voltage using the following procedure:
   1. Turn off the device power.
   2. Access the card cage and connect an anti-static strap to the banana jack.
   3. While wearing the anti-static strap, remove the MPE board and locate plug U212 (next to the PLL error LEDs). The 32-pin SmartSocket, with the 28-pin NVS memory chip plugged into the socket, is at the end opposite to pin 1.
      
   4. Measure the voltage across the corners of the memory chip on pin 14 (GND) and pin 28 (VCC) (pin 16 and pin 30 of the SmartSocket underneath it).

The voltage should be 4.5 V to 5.5 V. If the voltage is lower the data in the memory chip may be corrupted when the device’s power is turned off. However, the Smartsocket will use the device power supply when the power is turned on. This retains the data in memory, if the power is not switched off and the device can continue to operate until the MPE can be replaced.

Cause: Low NVS battery and low power supply
Solution: Measure the +5 V using the +5 V test point on the edge of the MPE board. The should be +5 V ±0.25 V If it is lower than 4.75 V, check the power connections on the backplane and check the power supply. If the +5 V is low, the output device may still operate, but the NVS will be sustained only by the battery. The SmartSocket will use whichever voltage is higher—the battery or the power supply.
If both the battery and the +5 V power supply are low, the NVS can be corrupted whether the device power is turned on or off.

Technical contact(s)

Al Edge

Submitted by

Al Edge

Date submitted

03 Apr 2007