Led_Keypad Illumination Problems - Siemens AX72 Service Manual

17 LED_Keypad illumination Problems

Fault Symptoms
Customer:
Main keypad illumination does not work
Exchange
keypad LED's
LED_ KEYPAD
Remove metal dome sheet before replace LED's Use soldering iron to remove defective component. Avoid
excessive heat! Watch surrounding components! Resolder new component afterwards. The metal dome jip
must be used to place the metal dome sheet.
E-commerce order number:
E-commerce order name:
Soldering temperature:
IRIS Diagnose Code:
Technical Documentation
TD_Repair_L1-L3_AX72_R1.1.pdf
LED Problems
Watch for oxidation and
damaged pads of the
LED's
not
Check the status of the
okay
LED's visually
not
okay
Use the diode test
function of a multimeter
to check the status of
the diode. The typical
voltage drop on the
diode is 1.7 V when
testing the diode
function with the
multimeter.
L36840-L2056-D670
LED AMBER
~ 360°C Tip Temp.
22000 Display / Background Illumination
Company Confidential
GRT:
Current measured failed
okay
okay
2006©BenQ
Release 1.1
Back to customer
without repair
caused by customer
SCRAP - has to be send
separately to WSC
- check for twisted or
bent contacts
- check for dry joints
Continue with
higher repair level
Page 39 of 41
01/2006