CIRCUIT DIAGRAMS
1. POWER(SMPS) CIRCUIT DIAGRAM
No Digitron Displayed
D128,R107,ZD151 are Defective
No Power |
-28VA No Power |
BD101,TH01 is Defective |
D127 is Defective |
IMPORTANT SAFETY NOTICE
WHEN SERVICING THIS CHASSIS, UNDER NO CIRCUMSTANCES SHOULD THE ORIGINAL DESIGN BE MODIFIED OR ALTERED WITHOUT PERMISSION FROM THE ALLEGRO ELECTRONICS CORPORATION. ALL COMPONENTS SHOULD BE REPLACED ONLY WITH TYPES IDENTICAL TO THOSE IN THE ORIGINAL
CIRCUIT. SPECIAL COMPONENTS ARE SHADED ON THE SCHEMATIC FOR EASY IDENTIFICATION.
THIS CIRCUIT DIAGRAM MAY OCCASIONALLY DIFFER FROM THE ACTUAL CIRCUIT USED. THIS WAY, IMPLEMENTATION OF THE LATEST SAFETY AND PERFORMANCE IMPROVEMENT CHANGES INTO THE SET IS NOT DELAYED UNTIL THE NEW SERVICE LITERATURE IS PRINTED.
|
|
|
28V No Power |
|
|
No Power |
|
Q120 or ZD153 are Defective |
|
|
|
|
|
|
|
D102 is Defective |
|
|
|
|
5.3VA No Power |
|
|
|
|
D121 is Defective |
|
|
|
|
30VA No Power |
12V No Power |
|
12V No Power |
Switching Error |
D130 is Defective |
D126 is Defective |
|
Q125 or ZD152 are Defective |
IC102,IC103 are Defective |
28V No Power |
|
|
|
|
|
D129 is Defective |
|
|
|
|
12V No Power |
|
|
|
|
IC157 is Defective |
|
|
|
|
|
|
2.5V No Power |
|
|
|
5V No Power |
IC152 is Defective |
|
S/W Error |
12V No Power |
|
|
|
IC151 is Defective |
|
||
|
IC107,Q111 is Defective |
D125 is Defective |
|
|
|
|
5V No Power |
|
|
|
|
D124 is Defective |
|
|
S/W Error |
1.8V No Power |
|
|
|
D123 is Defective |
|
|
|
|
IC101,IC104 is Defective |
|
|
|
|
|
|
|
|
|
|
|
|
|
1.8V No Power |
|
|
|
|
IC160 is Defective |
No Power |
3.3V No Power |
3.3V No Power |
|
|
F101 is Defective |
|
|||
D122 is Defective |
IC154 is Defective |
|
||
|
|
Switching Error
IC105,IC106 are Defective
NOTES) |
|
|
Symbol denotes AC ground. |
|
NOTE) |
Warning |
|
|
|
NOTE) |
Parts that are shaded are critical |
||
NOTES) |
Symbol denotes DC chassis ground. |
|
NOTE) |
With respect to risk of fire or |
||
|
|
|
|
|
NOTE) |
electricial shock. |
NOTE : |
|
1. Shaded( |
are critical for safety. Replace only |
with specified part number. |
|
2. Voltages |
DC-measured with a digital voltmeter |
during Play mode.
A |
B |
C |
D |
E |
F |
G |
H |
I |
J |
K |
L |
M |
N |
O |
P |
Q |
R |
S |
T |
3-32 |
3-33 |
2. SMPS P.C.BOARD
LOCATION GUIDE
3-60 |
3-61 |