Crazy LEDs (video inside) on Shruthi-1, what's wrong? [SOLVED]

So I’ve turned on my shruthi, which was unused about two weeks (Ambika is THAT good btw!), and I’ve encountered very strange behavior.
At the beginning everything works as it should, but then pushing buttons causes LED flickering and random menu diving, sound is normal though and MIDI works as should.

Looking at the solder joint they seem to me ok, so what’s the possible reason of this erratic behavior? Hope you can help me >_<

Photo of the digital board

Glitches at the beginning and the end of the video

This is not a “crazy” behavior but something that triggers the performance page. From the manual:

To jump to the performance page in which the 4 knobs control the user-defined parameters, hold S5 for more than 1s and release. While in the performance page, the LEDs indicate the current sequencer step, x0x style.

There might be something wrong with S5, the resistor network, or the 165 that causes a fake long key press.

Thank You for Your very quick reply Olivier! Here’s another one, where somehow turning a knob causes same madness. Can this happen because of somehow damaged ICs?

Hmmm… strange… it could be a short somewhere on the PCB, between adjacent pins.

So probably it’s not ICs? Jeez, desoldering again…

Have you tried firmly pushing down the ICs in their sockets?

Sorry guys, had a not so happy month in a hospital…

@t2k: At first it kinda worked, but hour later same shit started. I was happy that hour though :smiley:

Well, I just extracted solder everywhere possible, resoldered all joints and installed new 74hc165 and 74hc595. Everything is working perfect now! Thanks for help anyway