QSC ISA 280, Technical & Service Manual

Page: 127 / 142

Technical Service Manual 125
ISA Series Power Amplifiers
Gray shading indicates
signal path
A
3
SH–008001–00
REV
SH
D
W
G NO
.
ISA 800T
page 2 of 3
THIS DOCUMENT CONTAINS PROPRIETARY
INFORMATION THAT IS THE PROPERTY
OF QSC AUDIO PRODUCTS, WHICH MAY NOT
BE DISCLOSED, REPRODUCED OR USED
WITHOUT EXPRESS WRITTEN CONSENT FROM
QSC AUDIO PRODUCTS.
A
B
C
D
A
B
C
D
8 7 6 5 4 3 2 1
8 7 6 5 4 3 2 1
NOTES: UNLESS OTHERWISE SPECIFIED
CH.2 OUTPUT
AUTOFORMER
(CHASSIS-MOUNTED)
PLOT DATE:
Wed Sep 05, 2001
SCALE: NONE
SIZE
D
FSCM NO. DWG NO.
SHEET 4 OF 4
SH–008001–00
CAD FILE NO:
SH8001ra.sch
REV
A
CHANNEL 2 POS STEP DRIVER
NEG STEP DRIVER
DC FAULT
PROTECTION
PC–007503–00, DATAPORT PCB
PC–007504–00, DISPLAY PCB
PC–007505–00,
POWER LED PCB
CH 1
LINEAR
GAIN POT
CH 2
LINEAR
GAIN POT
R112
2.5K
R212
2.5K
SERIES REGULATOR
SUPPLIES APPROX
40MA TO HD-15 PORT
CONNECTS TO LOWER
POS. RAIL ON SAME
SIDE AS DISPLAY LEDs
BR MONO RETURN—CAUTION, SENSITIVE NODE
SW—GND FOR CLIP LIM
J401:1 J108:1
J401:2 J108:2
J401:3 J108:3
J421:2
J421:1
J421:3
J422:2 J106:2
J422:3 J106:3
J423:2 J206:2
J422:1 J106:1
J422:4 J106:4
J423:3 J206:3
J423:1 J206:1
J423:4 J206:4
J421:6
J421:5
J421:4
J402:1 J208:1
J402:2 J208:2
J402:3 J208:3
TO J5 & J6,
SH 2
SPEAKER BUS – BEFORE FUSE
J102:1
J102:2
J102:3
J50:1
J50:2
J50:3
J50:4
J50:5
J50:6
J50:7
J50:8
J50:9
J50:10
J50:11
J50:12
J50:13
J50:14
J50:15
J50:
HD–15 JACK
J202:1
J202:2
J202:3
J258:1–4
SEE SH 2
J258:7 & 8,
SH 3
J207:2
J207:1
J425:2
J425:1
J424:1
J424:2
J424:3
J424:4
J424:5
J424:6
J424:7
J424:8
J258:5
J258:6
TO J6,
SH 2
4–5 MA CHARGE CURRENT
1 MA DISCHARGE
TO J400,
PIN TO PIN,
SH 2
J105:1 J205:1
J105:2 J205:2
J105:3 J205:3
J105:4 J205:4
SEE SH 2