I have a defect mariko switch where the power button is not working. I already changed the ribbon cable and vol+ vol- is working - only power button does not have any function.
I cannot see any defect but do not know which parts are providing the power on function. Any information / help is appreciated.
Have done some readings - black probe to ground - I measured for the 4 pins on the connector:
Pin1 5,4 KOhm
Pin3 23,5 KOhm
Pin4 3,24 KOhm
Look carefully at the board, from your image there is a passive with a damaged endcap as well as signs of corrosion at board traces/vias, replace any damaged passive then scratch back the corroded traces and ensure you have continuity
@Severence thanks for your answer - I an not too experienced in these type of diagnoses - so still learning from day to day.
What I can see is that there was some corrosion in some test point - so assuming that the red marked lines are not working.
But before trying to bypass these (red) lines maybe someone knows if these will be needed for providing the power button function ? If so I’ll try to fix the trace…
For sure that trace going to the resistor from underneath the connector, you’ll need to jump that. The other one or two I’m not so sure but if you have a donor you can buzz it out in continuity to see where it’s supposed to be going and verify it that way
It would be wise to replace any resistors with damaged endcaps instead of trying to clean them up, as they will likely fail open at some point in time
Yes, the the right side test point goes straight down from the resistor there
@Severence thank you very much for taking your time and pushing me into the right direction.
With jumping the connection to the left resistor power button is working again.
Was the first time I did such a repair - so happy that it worked and I that people taking their time for helping!
Maybe not the best job, but working
Nice one, glad you got it sorted