ARISTO Cooker Hood: Unstable Functionality and Button Response Issues - Possible Triac or IC Fault?

Hello,
I know that similar topics have already been discussed here (moderators, please do not delete the post) but I have another question about this eaves. He is acting strangely. Sometimes there are no reactions to the buttons, sometimes it works well, sometimes it turns on and the engine speed is pendulum (from the lowest to the highest).
I took out the module, looked at it, corrected all February and worked fine for some time. Now the problem has returned. What could be the reason. Is a triac or integrated circuit?
For better orientation, I attach the module photos and descriptions on it:
on the board: 08086725, .... 26, .... 27, TOP SVA857 D, PI TI94V-0, on the chip: A 857-253_0_02, Under the paper sticker on the scalak: ST 62 T03 C 6/1 GK 6311 SB.
I am asking for help and information.
greetings

Welcome back,
Due to the fact that no one wrote back to my post, I had no choice but to do what I could. I mean, I "bathed" the entire plate in denatured alcohol, then I wiped it on both sides with a delicate brush (I removed the system from the stand). Later, I cleaned the chip itself, folded and operated for several days. Before cleaning under the magnifying glass, I noticed some foreign traces (like mold) under the system on the stand.
Keep it up.
greetings