HP -7035B Technical Manual page 55

PROBLEM
15. Y-axis acceleration too
slow.
16. X-axis acceleration too
slow.
17. Maximum pen speed too
slow.
18. Excessive Y-axis over-
shoot.
TABLE 7-1. 7035B TROUBLESHOOTING INDEX (Continued)
POSSIBLE CAUSE
a. Drive string too loose. Measure
tension per paragraph 5-66.
b. Input signal source impedance too high
(1 mv/inch, 0.4 mv/cm) range only.
c. Bearing in drive train faulty.
d. Faulty neon bulb in photochopper.
e. Excessive differential noise on
input signal.
f. Excessive friction.
a. Drive belt too loose. Measure
tension per paragraph 5-78.
b. Input signal source impedance too
high (1 mv/inch, 0.4 mv/cm)
range only.
c. Bearing in drive train faulty.
d. Faulty neon bulb in photochopper.
e. Excessive differential noise on
input signal.
f. Excessive friction.
a. Power line voltage too low. (Pen
speed is dependent on line voltage.)
b. Operating on 115-vol line with
voltage selector switch in 230-
volt position (front panel neon
won't light).
c. Bearing in drive train faulty.
d. Faulty neon in photochopper.
e. Excessive differential noise
on input signal.
f. Excessive friction.
a. Drive string too loose. Measure
tension per paragraph 5-66.
CURE
a. Tighten drive string
(see paragraph 5-67).
b. Lower source impedance and/or
increase amplifier gain (see
paragraph 5-92).
c. Replace bearing.
d. Replace bulb (aging not required).
e. See Table 1-1.
f. Clean and lubricate per
paragraphs 5-9 and 5-12.
a. Tighten drive belt
(paragraph 5-79).
b. Lower source impedance
and/or increase amplifier
gain (see paragraph 5-92).
c. Replace bearing (see
paragraph 5-87).
d. Replace bulb (aging not
required).
e. See Table 1-1.
f. Clean and lubricate per
paragraphs 5-9 and 5-12.
a. Increase line voltage (i.e.,
with Variac).
b. Correct switch position.
c. Replace bearing. (See
paragraph 5-87).
d. Replace faulty neon (no
aging required).
e. See Table 1-1.
f. Clean and lubricate per
paragraphs 5-9 and 5-12.
a. Tighten drive string
(paragraph 5-67).
7-5