Internal Modifications - Shure SCM410 User Manual

WARNING: Voltages in this equipment are hazardous to life. No user-serviceable parts inside. Refer all servicing to qualified
service personnel.
• Only make changes to jumpers (X) and resistors (R). The cir-
cuit board contains holes where resistors are to be added.
• For Channel modifications, the first character of the reference
designator indicates the channel number,(i.e., R1027 refers to
a Channel 1 resistor, X2001 refers to a Channel 2 jumper,
etc.). Modifications affecting the Master section are preceded
by a "9" (i.e., X9001).
DISASSEMBLING THE SCM410/SCM410E
To access the printed circuit board for internal modifications, proceed
as follows:
1. Remove the power cord from the ac power source.
2. Remove the knobs, retainer nuts, and washers from the front
panel, as shown in Figure 16
KNOB ASSEMBLY AND DISASSEMBLY
FIGURE 16
MODIFYING THE SCM410 FOR 220-240 VAC, 50/60 HZ OPERATION
As supplied, the SCM410 uses 100-120 Vac, 50/60 Hz power. To mod-
ify if for use with 220-240 Vac, 50/60 Hz power, proceed as follows:
Disassemble the SCM410 according to the procedures in the
1.
Disassembling the SCM410/SCM410E paragraph.
2. Locate Voltage Selector switch SW9001 adjacent to power trans-
former T9000.
MODIFYING THE SCM410E FOR 100-120 VAC, 50/60 HZ OPERATION
As supplied, the SCM410E uses 220-240 Vac, 50/60 Hz power. To
modify it for use with 100-120 Vac, 50/60 Hz power, proceed as follows:
Disassemble the SCM410E according to the procedures in
1.
the
Disassembling the SCM410/SCM410E paragraph.
2. Locate Voltage Selector switch SW9001 adjacent to power trans-
former T9000.
INSERTING A 12 DB MIC PREAMPLIFIER PAD
A microphone preamplifier channel gain can be reduced by 12 dB. This
may be desirable with high-output microphones.
DISABLING PHANTOM POWER BY CHANNEL
To disable phantom power for a given microphone input channel, re-
move the resistor specified in the following table

INTERNAL MODIFICATIONS

3.
4.
5.
3.
4.
5.
3.
4.
5.
1.
2.
15
• All Channel modifications in this section use Channel 1 as an
example.
Remove the four screws at each corner of the rear panel.
Remove the two screws at each bottom corner of the front panel.
Slide the back panel and printed circuit board out from the rear of
the chassis.
CAUTION: When reassembling the SCM410, DO NOT
OVERTIGHTEN the knob retainer nuts.Damage to the internal
components will result if too much force is used.
Using a screwdriver, turn the center rotor to the 230 position.
Locate Fuse F9000 and replace it with a T 50 mA L, 250 V, time
lag fuse for 220-240 Vac operation.
Replace the power cord with a cord rated for 220-240Vac operation.
Using a screwdriver, turn the center rotor to the 115 position.
Locate Fuse F9000 and replace it with a T 125 mA L, 250 Vac,
time delay fuse for 100-120 Vac operation.
Replace the power cord with a cord rated for 100-120 Vac oper-
ation.
Procedure:
Short jumper X1000.
Remove resistor R1006.
Channel Remove Resistor
1 R1005
2 R2005
3 R3005
4 R4005