IEC 30 Series - Page 46

SECTION 5
Table 5-1. Troubleshooting Guide (Continued)
Symptom/Step Possible Cause
Remarks
8.
OUTPUT LIMIT
LIGHT
FAULTS
(F32 thru F34)
a.
On prematurely 1.
Misadjustment of R166.
b. On
always
1. Q49 shorted.
2. Q48 open.
c.
Off
always
1.
Lamp failure.
2.
Q49 open.
3. Q48
shorted.
4. IC 18 faulty.
9.
GATE MODE
FAULTS
(F33/F34)
a.
No dynamic gating 1.
Trig level pot open circuit to ±15v.
2. Open
circuit from TRIG/SYNC BNC to R277.
3.
S9 faulty, open circuit to ground.
4. S6-2A, 4B open.
5.
6.
Logic
trouble.
Start/Stop trouble.
I
See step 22.
See step 23.
b.
No manual gating 1. S9 faulty.
2. 1 and 4 from 9a above.
c.
Incomplete last cycle
1.
S6 - 1B open.
2.
Logic
trouble.
See step 22.
3.
Start/Stop trouble.
See step 23.
d.
Baseline of triangle
and sine offset from
zero.
1.
2.
R228
misadjusted.
Start/Stop trouble.
See step 23.
e.
Baseline oscillation
Start/Stop trouble.
See step 23.
10. TRIGGER MODE
FAULTS (F33/F34)
a.
Double
triggers or
Incomplete cycle.
1.
2.
Start/Stop trouble.
Logic trouble.
I
See step 23.
See
step 22.
5-6