Allen&Heath DR128 SERVICE MANUAL - Manual (Page 70)

3
DR128 S
ERVICE
M
ANUAL
INTRODUCTION
The information presented in this section of the manual is intended for competent technical personnel to carry
out service and product support for the
DR 128
. We assume that the reader is familiar with the related electronic
theory and audio terminology, and is able to carry out basic servicing, fault-finding and repair of digital audio
equipment of this type. Service personnel should also be familiar with audio systems, mains earthing and power
requirements, as well as handling precautions.
For information on the installation, operation and application of the
DR 128
please refer to section
A of this manual.
Whilst we believe the information in this manual to be reliable we do not assume responsibility for inaccuracies.
We also reserve the right to make changes in the interest of further product development.
SERVICE AND TECHNICAL SUPPORT
Under normal operating conditions the
DR 128
does not require user maintenance or internal calibration. Any
service work required should be carried out by qualified technical personnel only.
We are able to offer further product support through our worldwide distribution network. To help us provide an
efficient service please quote the unit serial number, the date and place of purchase in any communication
regarding this product
SAFETY WARNING !
Mains electricity is dangerous and can kill. Mains voltage is present within the unit. Except for
Installation and calibration, do not remove any covers with power connected. Do not carry out any
work within the unit while it is powered. High voltage components are insulated for safety but should
not be touched with power applied. The mains voltage setting is indicated on the AC mains input
socket on the rear panel. Check that this matches your local mains supply. Check your mains wiring
and earthing before switching on.
DO NOT REMOVE THE MAINS EARTH CONNECTION!
The chassis is always connected to mains earth. Audio 0V connects to the chassis internally.
Should problems be encountered with ground loops operate the audio ground lift switches on other
equipment connected to the unit or disconnect the cable screens at one end. Refer to the section
on 'EARTHING' in the User Guide.
IMPORTANT STATIC ELECTRICITY
PRECAUTIONS
Many of the components in the
DR 128
are extremely sensitive to static electricity. The following
procedures reduce the possibility of damaging components:
1.) Before handling any components or touching anything inside the unit, discharge
your body's static electric charge by touching a grounded (earthed) surface.
Wear a grounding wrist strap if one is available.
2.) Do not remove parts from their antistatic containers or bags until you are ready
to install them. When removing circuit boards (PCBs) or chips from a unit,
immediately place them in an antistatic bag.
3.) When handling (PCBs), hold them by their edges and avoid touching the circuitry.
4.) Do not slide (PCBs) or ICs over any surface.
5.) Avoid having plastic, vinyl and foam in your work area.
6.) Limiting your movements during service work reduces static electricity.
WARNING: There is danger of explosion if the battery is incorrectly replaced.
Replace the battery with an Allen & Heath recommended part. Using a different battery, recharging or
dissassembling the battery may present a danger due to fire or explosion.
Dispose of used batteries promptly according to the manufacturer's instructions. Keep all batteries away
from childeren
Section B