Allen&Heath GL4000 SERVICE MANUAL - Manual (Page 13)

ALLEN & HEATH Section A - 8 L4DSM2
REMOVING A CHANNEL, GROUP, LEFT / RIGHT, MONO or MASTER
CIRCUIT BOARD ASSEMBLY
Before beginning any service work, remove all power to the console and disconnect any signal cables where necessary.
Service work is best carried out with the console inverted or positioned upright on its rear with the connectors removed.
Ensure adequate lighting and use the correct tools. Access to the CHANNEL, GROUP, LEFT/RIGHT, MONO or
MASTER circuit board is as follows:
1.) Before inverting the console, pull off the knobs and remove the pot nuts from the circuit assembly to be
removed. The switch caps can remain in place.
2.) With the console inverted or on its rear, remove the base and identify the circuit board to be removed.
3.) Disconnect the harness (A) plugged into the connectors mounted along the edge of the circuit boards..
4.) Carefully unplug the flat flexible cable (B) plugged into the circuit board asssembly to be removed.
WHEN REMOVING A CHANNEL CIRCUIT BOARD ASSEMBLY
Cut the Earth buss wire (G) on each side of the channel circuit board to be removed. Remember to resolder
the Earth buss wire (G) wire when channel circuit board has been replaced.
WHEN REMOVING A GROUP, LEFT/RIGHT or MONO CIRCUIT BOARD ASSEMBLY
The SLAVE circuit board assembly mounted across the GROUP, LEFT, RIGHT and MONO circuit board
assemblies in the master section of the console will have to be removed along with harness (D).
ALSO WHEN REMOVING THE RIGHT CIRCUIT BOARD ASSEMBLY
Harness (E) will have to be disconnected from the MONO circuit board along with harness (D).
ALSO WHEN REMOVING THE MONO CIRCUIT BOARD ASSEMBLY
Harness (E) and the flexible flat cable (F) will have to be disconnected from the MONO circuit board along
with harness (D). Take care not to stretch the DC power harness and fader wires still connected to the circuit
board assembly.
WHEN REMOVING THE MASTER CIRCUIT BOARD ASSEMBLY
The SLAVE circuit board assembly can remain in place, only harness (C) requires removal from both the
SLAVE and MASTER circuit board assemblies. The flexible flat cable, (F) and the green wire soldered onto
the trackside of the cicuit board will also need to be disconnected. Take care not to stretch the headphone
socket wires that are still connected.
5.) The circuit board can now be removed, take care not to stretch the fader wires that are still connected.
When all service work is complete, remove all debris such as solder, component legs and wire clippings from inside the
console and check your work carefully before reassembly. To refit the circuit assembly follow the above procedure in
reverse order. Make sure all harnesses are correctly aligned and plugged on. Test for correct operation.
GL4000-824 inverted with the base cover removed.
CONSOLE FRONT
C
E
SLAVE PCB
D
B B G
CONSOLE REAR
A
F