Troubleshooting Aid - HP 333A Operating And Service Manual

Model 333A/334A Section V
Table 5-8. Troubleshooting Aid
SYMPTOM
I
PROBABLE CAUSE
1. FRONT PA
A.
B.
C.
D.
E.
F.
G.
No meter deflection with signal a t input; ON lamp
not illuminated. (ALL FUNCTIONS).
No meter deflection with signal at input; Output
normal. (All FUNCTIONS).
Will nat null manually; VOLTMETER and SET
LEVEL FUNCTIONS normal.
No SENSITIVITY VERNIER control in SET
LEVEL mode.
BALANCE controls erratic. (DISTORTION
FUNCTION only).
No meter deflection with RF input. (R. F.
DET. only).
Low meter reading with input signal frequency
below 1 kHz. (Set Level Function only).
2. MTERNALAATl
A.
B.
C.
D.
E.
F.
G.
H .
J.
Insufficient -25 volts adjustment with AlR13,
measured at any violet wire.
+25 volts supply out of specs, measuredatany
red wire.
Insufficient bias adjustment with A2R3, meas-
ured a t A2TP1.
Insufficient bias adjustment with A2R20, meas-
ured
at
A2TP2.
Insufficient 400 Hz adjustment with A2R34.
Insufficient gain adjustment with A2R39.
Insufficient 3 MHz calibration adjustment with
A2c21.
Insufficient bias adjustment with A3R4, meas-
ured
at
A3TP1.
Insufficient bias adjustment with A3R16, meas-
ured at A3TP2.
EL SYMPTOMS
Check Fuse (Fl).
Check M1.
Check AIAF, CIA-D, C3, R4, R5, A6DS1, and
A6V1.
CheckR2, R3, andS2R8.
Check R4 and R5.
1a3
Check diode A4CR1. Spare diode located on out-
side of A4 shield.
Check to see
if
high pass filter is in the OUT
position.
TMENT SYMPTOMS
Check AlC1, AlC11, AlCR3, AlCR4, AlCR? and
A1Q4 through AlQ6.
Check -25 volts (see Symptom 2-A above), AlC2,
AlC6, AlCR1, AlCR2 and AlQlthroughAlQ3.
Check -25 volts (see Symptom 2-A above), A2C4,
A2C14 and A2Ql through A2Q4.
Check -25 volts (see Symptom 2-A above), +25
volts (see Symptom 2-B above), A2C15, A2Q5
through A2Q9.
check for -4 Vdc at + meter terminal and Check
M1.
Check +8.2 volts bias (see Symptom 2-Dabove),
Check A2Q5 through A2Q9, and A2C23.
Check A2C22. (Increasing value o f capacitor
will decrease meter reading).
Check -25 volts (see Symptom 2-A above), +25
volts (see Symptom 2-B above), A3C1, A3C6
and A3Q1 through A3Q3.
Check -25 volts (see Symptom 2-A above),
A3C7, and A3Q4 through A3Q6. Change
A3R17. (Increasing value o f resistor wilI
increase voltage
at
A3TP2.)
5-13