Agilent Technologies 2712A, 2948 manual F3 Memory Map Access

Service Model 8904A

6.Overvoltage Control Checks

a. On the Multifunction Synthesizer, press SHIFT PRESET. After the instrument presets, key in

For A3 Output Assembly	For A10 Output Assembly
SHIFT SERVICE	SHIFT SERVICE
NEXT NEXT	NEXT NEXT
f3 (Memory Map Access)	f3 (Memory Map Access)
NEXT NEXT NEXT NEXT	NEXT NEXT NEXT NEXT NEXT
80	80

b.Connect a dc coupled, high-impedance oscilloscope or logic probe to pin 12 of U2. The voltage should be a TTL low.

c.Press SHIFT. The voltage should be a TTL high.

NOTE

To repeat this part of the check, key in 80 then SHIFT. A beep will be heard each time 80 is keyed in.

d.Connect the oscilloscope or logic probe to pin 11of U2.

e.Key in 80 then SHIFT. As the shift key is pressed, the steady state TTL high should go momentarily low then back to high. (The logic probe should blink. The trace on an oscilloscope should blink perceptibly, or if the oscilloscopeis in the normal trigger mode, a single sweep should be triggered.)

f.Press SHIFT PRESET. After the instrument presets, momentarily short pin 10 of U2 to ground. The instrument should beep and the display should read

For A3:

Reverse Power Relay Tripped on Output 1

Press any key t o reset and continue.

For A10:

I Reverse Power Relay Tripped on Output 2 I

Press anv kev t o reset and continue.

8-36Troubleshooting (Digital/Output Interface)