Display/ Illumination Problems - Ericsson R250s PRO Troubleshooting Instructions

5 Display/ Illumination problems

5.1 Display problems
5.2 Type of fault
Insert a fully charged battery into the phone and start it up.
If the display is missing some of the segments, go to 5.1.1
If the display is empty, go to 5.1.2.
5.2.1 Segments are missing
Disassemble the phone and check for liquid damage.
No further action should be taken for a liquid damaged telephone.
Replace the display according to mechanical repair guide.
5.2.2 The display is empty
Disassemble the phone and check for liquid damage.
No further action should be taken for a liquid damaged telephone.
Replace the display according to mechanical repair instructions.
Give the board power and start it up with a display mounted. If the fault still remain, check
if the current consumption is less than 200 mA.
Remove the display from the holder.
Give the board power and start it up without the display mounted.
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1. RESETO (3.2V) is incorrect, measure the resistance from the pad to pin 77 of D600 ~0
ohm. Also check the soldering at that pin. If the resistance is substantially higher there is a
foil damage, send the unit on according to the local company directives. If the resistance is
correct, replace D600.
2. I2CCLK (3.2V) is incorrect, measure the resistance from the pad to pin 4 of D600 ~10
kohms. If it is higher, measure the resistance of R615 ~10 kohms.
3. GND is incorrect, i.e. there is too high resistance from the pad to ground, there is a foil
damage, send the unit on according to the local company directives.
4/00021-2/FEA 209 544/18 D
Measure the voltage at the display pads at H623.
If the resistance of R615 is correct there is a foil damage, send the unit on according to
the local company directives. Check VDIG (3.2V) at R620~2.2 kohms.
If all of the above is correct, replace D600.
Standard Trouble Shooting Instructions
18(35)