Installation guide

Troubleshooting
Troubleshooting Pulse Modulation and LF Out
1-109
4. Turn power on to the signal generator and configure it for pulse mode.
a. Press the
Pulse hardkey and the Pulse On softkey.
b. Press the
LF Out hardkey and the LF Out On softkey.
c. Press the
LF Out Amplitude softkey and use the numeric keypad to enter 5 Vp.
5. Use an oscilloscope and probe J12-23.
There should be a square wave with a period of 80 us and an amplitude of approximately 5 Vpp. The
period and pulse width of this signal may be varied using softkeys under the
Pulse menu.
• If the signal is present, replace the A13 Output.
(Refer to “A13 Output” on page 2-32.)
• If the signal is not present:
a. Turn power off to the signal generator.
b. Remove the A18 Reference. (Refer to “A18 Reference” on page 2-42.)
c. Insert a second ribbon cable extender into J53 on the A19 Daughterboard.
d. Ohm between J12-23 and J53-7 on the A19 Daughterboard.
— If the path is good, replace the A18 Reference.
(Refer to “A18 Reference” on page 2-42.)
— If the path is bad (open), replace the A19 Daughterboard.
(Refer to “A19 Daughterboard” on page 2-44.)