Console Functional Check - ALLEN & HEATH GS1 Service Manual

CONSOLE FUNCTIONAL CHECK

The GS1 undergoes several rigorous stages of testing and quality control before being despatched from the factory. The
following procedure is offered to the distributor, dealer and customer to confirm that the unit has arrived without damage
and in full working order.
1. Packing inspection
1.1 Check that the packed unit is intact and has not suffered unreasonable transit damage.
1.2 Carefully open the box and check the contents: GS1 console in polythene bag, power unit, User Manual,
Brochure, and orange Quality assurance card.
2. Cosmetic inspection
2.1 Carefully unpack the unit and check general cosmetic quality. Check that the plastic end caps and front
armrest are securely attached.
2.2 Set the controls ready for the electrical tests which follow: All faders down, Gains min, EQ mid, Aux
min, Level min, Pan mid, switches up.
3. Power-up and initial LED test
3.1 Check that the power unit is marked with the correct mains voltage. Plug the power unit DIN connector
into the GS1 AC 36V socket. Plug the power unit mains connector into the local mains outlet.
3.2 Apply mains power. Check that the MMC LED to the left of the mode switch lights. Press the MODE
switch and check that the MMC, PATCH and MIDI LEDs light in turn.
3.3 Press each CHANNEL ON switch in turn lighting the green ON LED. Press again to turn the channel
off.
3.4 Press each PFL switch and check that the red PFL ACTIVE LED lights in each case.
3.5 Press the Microphone PHANTOM POWER switch checking that the red PHANTOM POWER LED
lights. Measure +48V nominal between pin 3 (+ve) and pin 1 (-ve) and between pin 2 (+ve) and pin 1
of each mic XLR.
4. Patch Learn check
4.1 Press the MODE switch to select Patch mode. Press the LEARN switch. The LEARN LED should flash.
4.2 Turn all channels ON. Press MMC Function Key F1. Now press LEARN again. The Learn LED should
go out.
This has stored a patch with all channels on which is recalled by pressing function key F1.
4.3 Turn all channels off. Test that pressing F1 turns all channels on.
4.4 Remove power from the GS1. Wait about 30 seconds and power on again. Select Patch mode and check
that the patch F1 has been 'remembered' with power removed.
5. Signal test
The following tests check the audio inputs and outputs for signal flow and quality. This does not test every
routing combination but does check that all circuit blocks and input/output connections are working.
The equipment suggested includes a CD player with known good quality music or test signal material,
and a stereo amplifier with high quality loudspeakers. Where further technical equipment is available,
more accurate and comprehensive testing is possible using a sinewave signal source, dB voltmeter and
oscilloscope. This requires the necessary level of technical competence.
5.1 Plug CD player left output into TAPE RTN on Channel 1. Start CD playing and raise L-R fader to '0',
and raise Channel 1 TAPE RTN Level pot until the L, R meters both read an average '0' (first red LED).
Press the meters Lo switch to check that the meter reading decreases to average around '-10'.
5.2 Connect the GS1 2-TRACK outputs to the amplifier/speaker system. Listen for music quality equally
out of the L and R speakers. Test the operation of the TAPE RTN Level and Pan pots.
Replug and repeat for Channels 2 to 8.
5.3 Plug CD into Channel 1 Mic XLR. Press Line/XLR (pad) switch. Raise channel Fader to '0' and press
L-R. Adjust Gain for average '0' meter reading. Listen to music quality. Test Fader, EQ, Pan and
Channel On functions.
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ALLEN & HEATH