Ericsson R250s PRO Troubleshooting Instructions page 19

4. VDLCD (3.2V) is incorrect, measure the resistance from the pad to pin 45 of D600 ~0
ohm. If it is higher there is a foil damage, send the unit on according to the local
company directives. If it is correct, measure the resistance from the pad to ground (>2.5
Mohms). If it is incorrect, replace C615 and C674.If that does not help, replace D600.
5. VLCD (-2.7V) is incorrect, make sure that VDIG at N702 pin 5 is 3.2V.
Measure the resistance from the pad to pin 1 of V611 ~0 ohm. If it is too high there is a
foil damage, send the unit on according to the local company directives.
Check the soldering at D600 pins 95 and 96.
Measure the voltage at V611 (pin 1: -2.7V, pin 2: -1.6V, pin 3: -2.5V) and V608 (pin 1:
-1.6V, pin 2: 0V, pin 3: -1.0V).
If any of the voltages are incorrect, replace the corresponding diode and try again. If the
problem still remains, measure the resistance of C632, C634, C636 >2.5 Mohms, C631,
C633 >100 kohms and C824 >25 kohms.
If any of the resistances are incorrect, replace the corresponding capacitor.
Also measure the resistance of R616, R639 ~100 kohms, R807 ~82 kohms
and R808 ~33 kohms.
If any of the resistances are incorrect, replace the corresponding resistor. If the fault
remains, replace D600.
6. I2CDAT (3.2V) is incorrect, measure the resistance from the pad to pin 3 of D600 ~10
kohms. If it is higher, measure the resistance of R614 ~10 kohms.
If it is correct there is a foil damage, send the unit on according to the local company
directives. Check if there is VDIG voltage (3.2V) at R619 ~2.2 kohms.
If the voltage is lower, go to chapter On/ Off problems.
If all of the above is correct, replace D600.
7. If the fault is not fixed, send the unit on according to the local company directives.
5.3 Illumination problems
Disassemble the phone and check for liquid damage.
No further action should be taken for a liquid damaged telephone.
Make sure that all 15 LED's are correct mounted and soldered.
Replace the faulty component.
Give the board power and start it up.
The LED's H651-H654 and H662 are for the display light (group D LED's).
The LED's H655-H660 and H663-H666 are for the keyboard illumination (group K LED's).
At the start all the LED's should LIT for 10 sec.
Replace the faulty LED.
4/00021-2/FEA 209 544/18 D
Standard Trouble Shooting Instructions
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