Infinity ENTRA SUB TWO - Page 13

ENTRA SUB II POWER MODULE TESTING FLOW CHART
CAUTION : SPEAKER OUTPUT IS FLOATING AND IS NOT PROTECTED AGAINST A SHORT
TO GROUND. ALL TEST INSTRUMENTS CONNECTED TO THE OUTPUT MUST
BE FLOATING. ATTACH THE SCOPE PROBE TIP TO S - and REFERENCE
LEAD TO S+.
(A 10mV signal may need from the input to trigger the Switch turn on)
no
no
yes
yes
no
no
yes
yes
no
no
yes
yes
no
no
yes
yes
START
Check +/-15V-MOD
+/-15V voltage at
U 6(8),U6(4)
Discharge C37,
Check fuse
transformer, L4,
rectifier, C6 and C8
Use scope to chec
k
switching
frequency U6(7)
100KHz
+/-10% , ~24Vp-p
Check Q4(E)
TO V-
= 0V D.C.
Power up with no
signal input
LED RED
OK
OK
OK
OK
OK
OK
OK
OK
Chec
k
MUTE(+8V) and
Q24,Q25,Q26
Use scope to
check O/P U7(6)
and GND
143Vp-p square
wave shown
Chec
k
L2,L3,C71,C72,
C73
,
C74
I/P:10mv/50HZ
Check +15V/SW
Q4(E) TO V- =15V
Replace
Q18,Q22
CLASS D AMP O
K
END
Chec
k
U7,Q16,Q17,
Q20,Q21,R87,
D26,D35,C64
Chec
k
FB1,FB2,C45,
C50,C60,C63,
R81,R82
Chec
k
U7(1) = -58.3V
Chec
k
MUTE(-12.9V),
And
Q24,Q25,Q26
Resistance chec
k
(no load)
b
etween V+ V-,
V+ O/P,V- O/P
and O/P to GND
is > 10K
Entra Sub Two