Problem with buttons

Hi, i have just finished to solder my shruthi and everything seems to work well except for the first 2 buttons, starting from left, of my shruthi. To be more precise they are the 2 buttons of the voice selecion and the filter. When i press this two button the shruthi “jumps” to the the envelope and lfo section, as i would have pressed the third button, starting always from left, and, indeed the third led turns on, but i can’t go in the voice and the filter sections pushing this two buttons. The rotatory encoder allows me to go to the filter and voice section and to manipulate this parameters, they sound and work well, also the leds of the this buttons work well, so i think is something strictly connected with this two buttons, but what i should do? Help me please ! :frowning:

Check for shorts or bad solder points on the 165 and on the resistor network.

Hi, thank you for the answer; i re soldered some solder points that could be bad in the 220 transistor section and on the 165 chip on the digital board, but the problem stills!

sorry 220 resistor, not transistor

I have noticed that the two central 220 resistors are not perfectly completely covered, like the others transistors, with the blue film in the point in which the iron wire starts, this could be the reason of the disfunction?

The 220R resistors are limiting the current to the LEDs. If all LEDs are working, there’s nothing wrong with these parts. They are not related to the switches.

the leds work well; the solder points of the 165 chip seem good. What resistors should i check?

The resistor network RN1.

i try to resolde the 165 and the RN1 but without succes! I really don’t know know why these stupid buttons doesn’t work!

Probe pins 2 and 3 of the resistor network. Do they get from +5V to +0V when you press the buttons 1 and 2?

sorry for the stupid question, but the RN1 is the resistor under the midi socket or the one under the atmega?

Look at the bottom right of the board


Ok, now I got it! I’m stupid, i thought that the resistor in discussion was the R1… SHame On me, sorry! :frowning: :frowning: Tomorrow i’ll try to fix it, thank you very much for you extremely efficiency in answering my question, YOU HAVE BECOME MY PERSONAL GOD! Thank you!

HI, here the situation: i try to re solder the RN1, but nothing happens. The strange thing i noticed, before and after the re soldering of the RN1, is that SOMETIMES, let’s say once every 30 times, both buttons work! If i continuously push the first or the second button there is a little possibility that they respond in the right way. Now i try to check the voltage of the second and the third pin of the RN1 to see if they are correct

Is RN1 polarised correctly? The dot on the resistor network should be at the end furthest from the board edge.
Just another thing to check.




The RN1 was not polarized correctly! I desoldered it and re soldered in the correct way, and now everything works well! Thank you very much to every one for the support