Garmin 500W Series Instructions Manual page 10

2.5.1 Cleaning the Front Panel
The front bezel, keypad, and display can be cleaned with a soft cotton cloth dampened with clean water.
DO NOT use any chemical-cleaning agents. Care should be taken to avoid scratching the surface of the
display.
2.5.2 Display Backlight
The display backlight lamp is rated by the manufacturer as having a usable life of 20,000 hours. This life
may be more or less than the rated time depending on the operating conditions of the 500W Series unit.
Over time, the backlight lamp may dim and the display may not perform as well in direct sunlight
conditions. The user must determine by observation when the display brightness is not adequate.
Contact the Garmin factory repair station when the backlight lamp requires service.
2.5.3 Battery Replacement
The 500W series has an internal keep-alive battery that will last about 10 years. The battery is used for
GPS system information. Regular planned replacement is not necessary. The 500W series will display a
'low battery' message when replacement is required. Once the low battery message is displayed, the
battery should be replaced within 1 to 2 months.
If the battery is not replaced and becomes totally discharged, the 500W Series unit will remain fully
operational, but the GPS signal acquisition time may be increased. This acquisition time can be reduced
by entering a new seed position each time the unit is powered on. There is no loss of function or
accuracy of the 500W Series unit with a dead battery.
The battery must be replaced by the Garmin factory repair station or factory authorized repair station.
500W Series
Instructions for Continued Airworthiness Bell 206B
In the event of bonding test failure:
1. Inspect the grounding strap which is installed between the
annunciator and the instrument panel. Ensure that the
fastener hardware is secure and that the strap is not
damaged. If damaged, replace the bonding strap.
2. If problem persists, remove the bonding strap and clean the
mating surfaces of the bonding strap and
annunciator/instrument panel per Bell specification BHT-
ELEC-SPM CHP8.
3. Reinstall the bonding strap and verify that the resistance
between the annunciators and the console assembly after
prepping bonding surface is less than 10 milliohms.
190-01226-03 Rev. 5
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