Ecler MPA4-150, Service Manual

Page: 139 / 149

author:
Queralt
date:
000718
approved:
num:
51.0023
version:
01.00
VERIFICATION PROCESS
title:
EP05-99
ECLER
other oscillations.
- Repeat the same process with the remaining channels.
QUALITY CONTROL
All mechanical parts should be visually revised, in order to detect scratches on the
unit's painting; all screws should be on their place,correctly tight and unmarked. Check
out the unit's general presentation.
BURNING (BURN-IN) TEST
Leave the tested unit connected to its correspondent voltage mains socket, applying
input signal and connecting load impedances, and working at 3dB under its maximum
output power level for at least 24 hours.
VERIFICATION USING MUSIC
Verify the unit's sound quality, which should be distorsion- and noise-free. Also check
that all potentiometers can run smoothly their whole sweep, without annoying noises
and crisperings. At their minimum position, check that output signal is completely
cutted off. To ensure that all electrical junctions are well-fixed, hit the tested unit
against your working table, obviously without damaging its outer presentation. Verify
also all inputs and outputs. Also verify the HPF and LPF filters' performance. At last,
short-circuit the output terminals while carrying amplified signal, and verify that once
short-circuit is removed, the amplifying stages still are working.
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