Samsung SPH-A640 User Manual page 214

1.
Press Menu > Settings > Display > Backlight.
2.
Select Main Display or Keypad and press
3.
Select the minimum time setting (8 seconds) and press
Use phones with a pull-out antenna. Phones with embedded antennae may produce
more interference.
Position the phone so the antenna is farthest from your hearing aid.
Move the phone around to find the point with least interference.
196 Section 4A: Important Safety Information
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