Vivitar 283 Service Manual page 34

Automatic Electronic Flash
Model 283
4. TROUBLE:
No flash, ready light and oscillator working- trigger circuit not functioning-sensor fitted ·
to strobe unit.
ACTION INDICATION REMARKS
A. Check trigger voltage at hot shoe contacts, or in- 230V approx . Go to step B
sert PC cord and measure at PC cord receptacle
No voltage Go to step C
B. Check for arcing at PC cord receptacle or across Arcs Go to step D
hot shoe contacts
No arc Go to step E
c.
Check trigger capacitor C7 for short No short Go to step E
Short Replace C7
D. Check potent
ial across xenon flashtube FT1 330V approx. Replace C7
No voltage Check connections to
L 1 and to flashtube
FT1 for continuity,
SCR2 for open circuit,
and trigger lead connec-
ti on
E.
Check D5 and R 12 for open circuit
If OK
Check trigger coil T2
and PC board connec-
tions
If open Replace defective com·
ponent
~.
TROUBLE :
Low light level-manual mode.
ACTION
INDICATION
REMARKS
A. Check voltage across C1 (see Sec. 4 .2.4) 320V Go to step D
Less than 320V Go to step B if it can-
not be adjusted at R6
B. Check battery, inspect protective insulation, GOOD Go to step C
look for arcing traces on PC board near C1
BAD Replace battery or C1 ,
~s
necessary
c.
Check C1 for leakage and capacitance
GOOD
Go to step D
BAD Replace C1
D. Check flashtube FT1 for discoloration
NONE Check alignment of·
xenon tube, cleanliness
of diffused lens and re·
flector
Discolored
Replace FT1
'28
Vivitar 37460596 (11/80)
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