On an OptiX OSN 3500 NE of NE version 220.127.116.11, the XCE on the extended subrack is reset. At the same time, the NE reports the BD_STATUS alarm. One minute later, the NE reports the going-online event and HSC_UNAVAIL alarm. The HSC_UNAVAIL alarm disappears four minutes later.
Replace the XCE with an XCE manufactured after April 2007.
The 1.8 V voltage supply is designed too high for the SSN1XCE. The OptiX OSN 3500 has tightened voltage detection since V100R006. Therefore, the high voltage supply is prone to crossing the threshold. In addition, instead of being as direct as a line, the wave of a DC power supply is subject to fluctuations and burrs. Therefore, the DC power supply requires a reasonable voltage allowance. If the allowance is too low, the voltage is likely to cross the threshold and to cause the board to reset. This problem is common to the XCEs manufactured before April 2007.