Agilent Technologies 5517B Operation And Service Manual page 92

Upon successful completion of a check, unless otherwise specified, return all test jumpers to their original position
[i.e., left-most NRM position)].
A TILDE ("-") PRECEDING ALL SIGNALS INDICATES NEGATIVE-TRUE LOGIC.
a. With power disconnected, remove front panel and side covers as described in paragraph 8-57.
b. Set HEATER JMP7 to OFF. Position all remaining jumpers to the left. Apply power to laser head. Measure clock
frequency at TP5 (CLK). If it is 100 Hz ± 20% go to step c. if not, check clock section components.
c. Remove CLOCK FREQUENCY jumper completely. If clock frequency is now 75 kHz ±20%, go to step d. If not,
check A3C3 and A3C7.
d. Set HTR OK to HI and -REF ON jumper to HI. Connect signature analyzer test leads to A3 test points 4 through
7 as follows: black lead to TP4 ("GND"), yellow lead to TP5 ("CLK"), red lead to TP6 ("STP"), and green lead to
TP7. Set up signature analysis Clock, Start, and Stop signals for falling edge detection. Take signatures on
A3XU9.
Pin 16 (+5 V Test Signature)
Pin 2 5653
Pin 3 2333
Pin 5 - 3357
Pin 7 U729
Pin 10 HP8P
Pin 11 6PCP
Pin 12 0148
Pin 13 A10H
U19 (Pin 10) A957
If these are OK, go to step n.
If the signature analyzer will not take signatures, then there is a malfunction in the dividers or power-on-reset
sections. Go to step e.
If the signature analyzer works, but one or more signatures are wrong, go to step f.
Test jumpers remain in place if continuing with step e. If ending test procedure at this point, return all test jumpers
to their left-most position.
e. Set HTR OK to HI, -REF ON to HI, and RESET to TEST. Connect A3TP2, A3TP3, and Pin "X" of HTR OK jumper
to ground (A3TP1 or A3TP18). Verify the dividers by measuring the frequencies at the IC pins indicated in
8-3
and determine if they are equal to the indicated ratios, i.e. the frequency at A3U6 (Pin 13) should be equal to
the frequency at A3TP5 divided by 1 6.
The counter function of the signature analyzer may not work so a dedicated counter might be needed.
Measure Frequency at IC
pin
U6 13
U4 15
NOTE
104C
NOTE
Frequency should be equal to
ratio of
= F(TP5/16)U6
OR - 4.8kHz
i
F(U6 pin 13/16)
If Incorrect, faulty part
is:
U4 or U6
Table