681XXC OM 6-7
Error Message Description/Remarks
Error138
SDMUnit or Driver Failed Indicatesa failure of the switched doubler module (SDM) or SDM bias regulator cir -
cuitryon the A14 PCB. The 681XXC is still operable but it will not produce an RF
outputin the 20 - 40 GHz frequency range.
Error139
32–40 GHz SDM Section Failed Indicatesa failure in the 32 - 40 GHz switched doubler filter path within the SDM.
The681XXC is still operable but it will not produce an RF output in the 32 - 40 GHz
frequencyrange.
Error140
25–32 GHz SDM Section Failed Indicatesa failure in the 25 - 32 GHz switched doubler filter path within the SDM.
The681XXC is still operable but it will not produce an RF output in the 25 - 32 GHz
frequencyrange.
Error141
20–25 GHz SDM Section Failed Indicatesa failure in the 20 - 25 GHz switched doubler filter path within the SDM.
The681XXC is still operable but it will not produce an RF output in the 20 - 25 GHz
frequencyrange.
Error142
Sampleand Hold Circuit
Failed
Indicatesa failure of the sample and hold circuitry on the A10 PCB. The 681XXC
stilloperates normally but the RF output may be unleveled during square wave
modulation.
Error143
SlopeDAC Failed Indicatesa failure of the level slope DAC on the A10 PCB. The 681XXC still
operatesnormally but RF output level flatness may be affected during analog
frequencysweeps.
Table6-1. Self-TestError Messages (4 of 4)
OPERATOR ERROR AND WARNING/
MAINTENANCE STATUS MESSAGES