Ericsson T18s Trouble-Shooting Instruction page 51

Measure the resistance from pin 91 of D600 to the marked side of R651 (~0 ohms,
fig. 9.1).
• If it's correct, measure the resistance of R651 (1 kohms, fig. 9.1).
* If it's incorrect, replace R651 (class A).
* If the resistance is correct, replace D600 (class B).
• If the resistance is incorrect there's a foil damage and the phone is to be dis-
carded.
9.3 Display illumination missing or faintly
glowing.
Open the phone and check for liquid damages.
Make sure all the LEDs (H651-H654, class A, fig. 9.1) are mounted and correctly
soldered.
Give the board power and start it up.
If one or a few of the LEDs aren't lit, measure the voltage of the LED from one side
to another.
• If the voltage is ~1.7V then the LED is faulty and is to be replaced.
4/00021-2/FEA 209 544/12.B
T18s, T18sc Standard Electrical Repairs
Fig. 9.2
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