Garmin GNC 420, Руководство по обслуживанию

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400 SERIES MAINTENANCE MANUAL Page 4-1
P/N 190-00140-05 Rev. C
SECTION 4
DISASSEMBLY AND ASSEMBLY
4.1 INTRODUCTION
Repairing the unit is accomplished by removing and replacing defective boards. To help
disassemble and reassemble the unit in order to access the boards, look at the assembly drawings
in Section 7 and the parts lists in Section 6.
Each unit in the 400 Series contains static sensitive components.
Observe proper anti-static procedures when testing the unit.
Do not replace assemblies with the unit turned on. Hazardous
voltages exist on the Inverter Board (Figure 7-2, Item
012-00256-00). Under normal operating conditions the
voltages range up to 2500 V ac peak to peak. Under open
circuit conditions voltages can range over 8000 V ac peak to
peak. Remove all power to the unit and wait at least six
minutes before starting disassembly. Death or serious injury
could result from electrical shock.
4.2 REQUIRED TOOLS
Standard shop equipment can be used to remove and replace defective boards.
The 400 Series lens is coated with a special anti-reflective
coating which is very sensitive to skin oils, waxes and abrasive
cleaners. CLEANERS CONTAINING AMMONIA WILL
HARM THE ANTI-REFLECTIVE COATING. It is very
important to clean the lens using an eyeglass lens cleaner which
is specified as safe for anti-reflective coatings and a clean, lint-
free cloth.