A6 Front Panel Interface Scan Assembly Troubleshooting - Keysight N5171B EXG Service Manual

Troubleshooting
Troubleshooting Assembly Level Problems

A6 Front Panel Interface Scan Assembly Troubleshooting

The A6 Front Panel Interface Scan assembly is a Liquid Crystal Display drive
assembly that provides the necessary interface, control and circuits for the
complete front panel. Front panel USB connectors, the LCD back-light control,
Keypad, Power On/Off switch, and the LCD support circuitry are all interrelated
within this assembly. Unlike other similar display drive assemblies this
assembly is low voltage; 5 VCD or less.
There are no specific automated self-tests associated directly on or for the
front panel, except for the related different supply voltages coming from the
power supply and the A3 RF assembly via ribbon cable W1.
The A6 Front Panel Interface Scan assembly has a boot-up routine it goes
through when the instrument is initially powered up. During this routine,
different lower level functions are initiated and verified. If the Interface Scan
assembly completes its boot-up sequence the assembly functionality is
potentially not at fault. Depending on the observed instrument failure, the
faulty component may be an independent failing mechanism that is connected
to the Interface Scan assembly; i.e. Keypad assembly or connecting ribbon
cable, Front Panel LCD Display or Backlight, etc....
To determine if the A6 Front Panel Interface Scan assembly is faulty, verify the
completion of the following boot-up sequence.
1. Turn the signal generator off.
2. Using Figure 1-8 locate the DS5, DS6, and the Debug LEDs (off) DS20 -
DS27.
Figure 1-8 LED DS1 and A6J5-1
Keysight X-Series Signal Generators Service Guide 53