OHAUS CKW-55, Руководство по обслуживанию

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CHAPTER 1 INTRODUCTION
1.4 SERVICE STRATEGY
The repair method for the CKW-55 Indicator is the direct replacement of major assemblies.
The CKW-55 Indicator contains the following replaceable assemblies: Cover Assembly with Membrane
Switch, Main PC Board with LED and Bar Displays, and Power Supply PCB. Optional assemblies consist
of: NiMH Rechargeable Battery, Battery Recharge PCB, RS422/485 Communication PCB, and an AC or
DC Relay Board.
This service manual contains sufficient information to isolate the problem, replace the assembly, test and
restore the Indicator to original factory specifications.
1.5 SAFETY AND ENVIRONMENTAL PROTECTION
When carrying out service or repair work, always observe the following.
• Before opening the Indicator, isolate it from the AC power line (pull out the
plug).
• The Indicator contains sensitive electronic components that are sensitive to
electrostatic discharge . We recommend that you wear a grounding wrist
strap when doing any work in the interior of the Indicator, in order to prevent
any electrostatic charge building up. Grounding wrist straps are commercially
available from electronic component suppliers. Use only ground straps that
include a protective series resistor in the assembly.
• Indicators have a built-in memory backup battery and may contain an optional
rechargeable battery. These contain heavy metals which could be hazardous
to the environment. Batteries must not be disposed of as normal domestic
refuse. Please ensure that used, non-working batteries are disposed of
correctly in accordance with the relevant local regulations.
• When this symbol is displayed, important information regarding mainte-
nance instructions should be carefully read before proceeding.