Technical data
5 Troubleshooting Guide
52 N1911A/1912A P-Series Power Meters Service Guide
Instrument Self-Test
Instrument Purpose Debug Tips Possible Faults
Test point voltages Checks that all of the supply 
voltages are present
Replace the PSU to see if this 
clears the faults
PSU (low probability) 
Main board (high probability)
Calibrator Verifies that the calibrator is 
working
(Note: This test does not 
check that the calibrator 
meets its specifications)
Check/reseat that cable 
between the Calibrator 
Assembly and the Main Board
Attempt to adjust the 1 mW 
Power Reference Level
Calibrator assembly (high 
probability) 
Main board (low probability)
Fan Verifies that the fan is 
working
Check/reseat the cable 
between the Fan Assembly 
and the Main Board
Check visually to see whether 
or not the Fan is working
Fan assembly (high 
probability)
Main Board (low probability)
Battery Checks that the lithium 
manganese battery on the 
main board is working
Replace the battery to see if 
this clears the fault
(Note: It is recommended for 
the battery to be replaced at 
the Keysight service center 
every five years)
Lithium manganese battery 
(high probability)
Main board (low 
probability)
Peak path/ChA peak path Verifies that the peak path of 
channel A is working
(Note: This does not prove 
that the peak path meets its 
specifications)
Replace the DAP Assembly 
for Channel A to see if this 
clears the fault
DAP assembly, channel A 
(low probability)
Main board (low probability)
CW path/ChA CW path Verifies that the average 
path of channel A is 
working (Note: This does 
not prove that the average 
path meets its 
specifications)
Not applicable Main board
DAP check/ChA DAP pheck Executes an internal self-test 
procedure on the DAP 
Assembly for channel A
Replace the DAP assembly for 
channel A to see if this clears 
the fault
DAP assembly, channel A 
(high probability)
Main board (low probability)










