Shure SCM800E manual Internal Modifications, Removing the TOP Cover

INTERNAL MODIFICATIONS

WARNING: All modifications must be performed by quali- fied service technicians. Voltages in this equipment are haz- ardous to life. No user-serviceable parts inside. Refer all servicing to qualified service personnel. The safety certifica- tions of the SCM800 do not apply when the operating volt- age is changed from the factory setting.

ABOUT PRINTED CIRCUIT BOARD MODIFICATIONS

SA jumper is represented by “X” on the printed circuit board legend, a resistor is represented by an “R.”

SThe first number in the reference designator indicates the channel number; i.e., R1027 refers to a Channel 1 resistor, and X7216 refers to a Channel 7 jumper, etc.

SComponents in the Master section are preceded by the number “9” (X901, etc.).

SThe circuit board contains holes where resistors are to be added.

SA single drop of solder can serve as a jumper between adjacent jumper pads.

SAll Channel modifications in this section use Channel 1 as an example.

REMOVING THE TOP COVER

To gain access to the main printed circuit board, remove the eight Phillips head screws securing the top cover to the chas- sis and remove it. Most internal modifications can be made from the top of the main board.

MODIFYING THE SCM800 FOR 220–240 VAC, 50/60 HZ OPERATION

The SCM800 can be internally modified to operate on 230 Vac, 50/60 Hz power.

NOTE: The supplied cord uses Harmonized IEC Cordage with

the following color coding: Brown = Line, Blue = Neutral, Green/Yellow = Ground. For systems requiring other mains connectors, obtain a power cord with an IEC 320 type mating connector for connection to the SCM800, and an appropriate plug on the other end for connection to the mains.

Procedure:
1.	Disconnect the SCM800 from the AC power source.
2.	Remove the top cover.
3.	Locate Voltage Selector switch SW903 adjacent to power
	transformer T901. Use a screwdriver to turn the center ro-
	tor on the SW903 to the 230V position.
4.	Locate Fuse F901 and remove it. Replace it with a 100
	mA, 250 V, time delay fuse for 230V operation. Fuse part
	numbers are listed in following table:
	Fuse Type	Shure Part No.	Littelfuse Part No.
100 mA, 250 V		80C258	218.100
200 mA, 250 V		80BC8196	239.200
5.	Replace the power cord with a cord rated for for 230V op-
	eration, i.e., an IEC appliance connector on the equip-

ment end and a CEE 7/7 (“Schuko”) mains connector on the other.

MODIFYING THE SCM800E FOR 100–120 VAC, 50/60 HZ OPERATION

The SCM800E can be internally modified to operate on 120 Vac, 50/60 Hz power.

NOTE: The supplied cord uses Harmonized IEC Cordage with

the following color coding: Brown = Line, Blue = Neutral, Green/Yellow = Ground. For systems requiring other mains connectors, obtain a power cord with an IEC 320 type mating connector for connection to the SCM800E, and an appropriate plug on the other end for connection to the mains.

Procedure:
1.	Disconnect the SCM800E from the AC power source.
2.	Remove the top cover.
3.	Locate Voltage Selector switch SW903 adjacent to power
	transformer T901. Use a screwdriver to turn the center ro-
	tor on the SW903 to the 120V position.
4.	Locate Fuse F901 and remove it. Replace it with a 200
	mA, 250 V time delay fuse for 120 V operation. Fuse part
	numbers are listed in the following table:
	Fuse Type	Shure Part No.	Littelfuse Part No.
	200 mA, 250 V	80BC8196	239.200
	100 mA, 250 V	80C258	218.100
5.	Replace the power cord with a cord rated for 120V opera-
	tion, i.e., an IEC appliance connector on the equipment
	end and a mains connector suitable for 120V operation on
	the other.

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