Elmo st-I200, Service Manual

Page: 29 / 40

SOUND (Cont'd)
Case Step Point Remark
Magnetic recording
cannot be effected Recording knob
assy
(P7-k)
Check the breakage of Recording knob assy by
a tester.
AMP assy
(P7-j) Check Sound head whether the adequate bias
voltage has been effected.
If not, replace AMP assy.
*Bias voltage:
Single recording .. 30-50V A.C.
Double recording .. 25-30V A.C.
Check the breakage of Tr3 in AMP assy to find
out the damage of high frequency circuit in
AMP assy.
If so, replace AMP assy.
Recording level is
low AMP assy
(P7-j) Check the bias voltage of Sound head to find
out under-bias current.
If so, replace AMP assy.
Sound head
(P5-56) If Sound head has been exhausted or broken,
replace Sound head. P-18
Head presser
(P5-51)
If the film cannot be held in parallel with Head
presser and Sound head, adjust the position of
Head presser holder assy.
P-18
Film If the sound track of film has been exhausted,
replace film.
Output sound is low
during optical
recorded film
reproduction
Exciter lamp
(P5-68) Adjust the position of Exciter lamp if it has
been distorted. P-17
Sound lens
(P5-81)
Adjust the angle and position of Sound lens if it
has been distorted.
If Sound lens has been stained, replace.
P-17
Silicon photo diode
(P5-77)
Check the breakage of Silicon photo diode and
if so, replace.
P-17
AMP assy
(P7-j) Check the output voltages on Circuit plate in
comparison with the voltage checking points on
AMP circuit plate and if the unusual voltage
would be measured, replace AMP assy.
P-34
Film Recording level of the film loaded is low.
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