HP 212A - Page 30

SYMPTOM
DEFECTIVE
( COMPONENT
SUGGESTIONS - CAUTIONS - CHECKS - ETC.
18. NO PULSE VISIBLE -
TRIGGER PULSE
VISIBLE
PULSE HIGHER THAN
THAT OF POSITIVE
PULSE
2 1. INSUFFICIENT PULSE
ADVANCE
V11 or
power source for VE 1
Replace V 11. Check maximum pulse amplitude.
Replace defective component in power supply.
Check maximum pulse amplitude and regulated
supply voltage output per instruction manual.
I Replace R2 1.
Replace R22.
SlOl switch cir-
cuitry, shielded
cables, etc.
R22
In instruments having
two parallel 100 ohm
resistors for R22, check
value of resistance
Replace V102.
Replace defective resistor.
Replace V101.
Check zero and maximum
advance and microphonics.
Replace CR101. Check SYNC OUT pulse.
Check winding continuity of T 10 1.
Following
replacement, check SYNC OUT pulse shape.
Check continuity and resistance to ground at
points in sync output circuit,
Replace V 10 1. Check maximum advance
obtainable, position of 0 advance on PULSE
POSITION control and rnicrophonics.