Moog Satellite - Page 25

SYMPTOMS
Regulated -9 volts
out of tolerance
Excessive Ripple
on -9 volts
No keyboard vol¬
tage
Keyboard voltage
not adjustable
No trig signal
PROBABLE CAUSE
CORRECTION
Bad regulator
1. Replace IC2
2.
Replace Ql
3.
Check R8, R6, R7
Bad regulator
1.
Replace IC2
2.
Replace Ql
3.
Check R8, R6, R7
Load exceeds 50ma
1. Measure resistance of
-9 volts to ground
nominal value 1000 ohm.
2.
Check C2.
Raw DC low
1.
Transformer T1
2.
Diodes Dl - D4
3.
Filter cans
Excessive ripple
1.
Filter caps
on raw DC
2. Diodes
3.
Transformer
Bad Regulator
1. Replace IC2
2. Replace Q2
3.
Check C2
Keyboard shorted
1.
Remove short
Ground on keyboard
string
1. Remove short to ground
Keyboard resistor
1. Replace bad resistor
string open
2.
Fix open
Bad current source
1. Replace IC7
2. Check R80, R79, R81,
-
R82
No keyboard voltage
1.
Check keyboard current
source
2.
Check keyboard buss
connection
3.
Replace IC4
4.
Check R53