Selected Components - Tektronix DC 5010 Anleitung

Two physically adjacent points having the same signa-
ture, whether one or both are incorrect, may indicate they
are shorted together.
A point with 0000 signature is grounded, or in a low
state. A point with the +5 V signature (noted on each signa-
ture diagram) may be opened or the driving node may be
stuck in the high state. The point might also be shorted to
+5
v.
When the malfunction has been identified and corrected,
carefully re-insert the Digital board microprocessor, making
certain that pin 1 is properly oriented and all pins insert in
the socket properly. DO NOT FORCE the pins.
Selected Components (R1307 and R1326)
Refer to diagram 2 (board A12) in the pullout pages for
the following.
If IC's U1310 and U1330 (M234 Type) are replaced and
the input sensitivity (50 a) is found to exceed 57 mV peak-
to-peak at 100
MHz
(25°C ambient temperature), the fol-
lowing procedure is recommended.
NOTE
If IC's U 1310 and U 1330 (M234) should have to be
replaced, the input sensitivity is unlikely to vary.
The values of selected resistors, R1307 and R1326
(nominal value of 1.4 K C ? each) may be changed to alter the
input sensitivity for channels A and B respectively.
If the instrument requires more than a 57 mV peak-to-
peak signal to trigger it, the resistance values of R1307 and
R1326 will need to increase. The sensitivity will change ap-
proximately 10 mV p-p forleach 500 ohms of resistance
change.
REV OCT 1981