How to solve a headphone not detected problem on a Nokia 101 (RM-769)

For this job you'll need a digital multimeter with a continuity test and a basic soldering iron (30W will be enough).

Image #2

 Set you multimeter to a continuity test mode (see image #3)

Image #3

Image #4

and on a mainboard of a phone check if there is a connection between 2 pins of a headphone connector. These pins are shown on the Image #4 and they are marked as #1 and #2. Also a headphone jack must be inserted in the headphone connector while doing the continuity test. This process will look like something like this:

Image #5

if there is no connection between these 2 pins (while headphone is inserted) than you'll have to desolder the headphone connector from the mainboard of the phone and than solder a new one there.

Let's say that there is no problem with the headphone connector (or there was a problem and you replaced it with a new one) and there is a connection between the 2 pins of it (see image #4), than there are 2 ways how to fix the headphone not detected problem:

Image #6

1) The first way is to desolder the smd part #1 (see Image #6), which itself is a resistor (value for this resistor is 470 ohm), and than solder there a new smd resistor (470 ohm).

2) The second way is to desolder the smd part #1 (see Image #6) and jumper the two contacts where the smd part #1 was soldered.

Now your phone will detect your headphone. That's all, job done.