6
Replacing Major Components
6.4
Opening the case
AT-10 plus
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6.4 Opening the case
The top assembly is secured to the base assembly with seven recessed screws.
Access to the screws is gained from the underside of the unit. To remove the Top
Assembly, proceed as follows:
1. Turn the unit up-side-down and rest on a soft antistatic cloth.
2. Unscrew and remove the countersunk retaining screws and washers situated in
the extreme corners and edges of the unit.
3. Grasping the top and bottom of the unit to ensure that the two assemblies cannot
part, carefully return the unit to the standing position.
Before commencing any removal or replacement procedures ensure that the mains
power supply is switched off and that the mains cable is removed.
• The AT-10 plus contains static sensitive CMOS components; observe antistatic
precautions:
• When carrying out any maintenance procedures always place the unit on an
earthed antistatic mat.
• Personnel must be earthed when handling any boards or components.
• Always use an antistatic bag when transporting boards or components.
• The unit is susceptible to abrasion damage. To prevent scratching, always place
the unit on a soft, non-abrasive cloth when carrying out maintenance procedures.
• Take care not to place any strain on the connecting ribbon cable when removing
the top assembly. Ensure that the cable assembly is not crimped or twisted and
that the top assembly is not placed on the cable assembly.
• Care must be taken when removing and replacing connectors. Never use force.
Never strain the cable assemblies.
V
Before reassembly a full sight must be carried out (see page 49).
V
After reassembly the functional and safety tests must be carried out according to
the checklist at the end of this book (see page 73).
• Philips screwdriver 1
• Low abrasion antistatic mat
x4
