Thank you for the answer. Really helpful. Yes i definitely have a plan to use some arduino but jut trying to learns basics about components and using some practical idea like 20 minutes timer to relax eyes as a motive to continue. thanks

I am trying to use 10 MegaOhm resistor with 20K in 555 timer and that might be the case why blue capacitor (ELECTROLYTIC 47 uF) or 555 timer not working and it is making me mad from many days as per part of your answer -

You had written Awesome without being a chemist! +1

Again thank you, really appreciate you for such great answer. Though they are dirt cheap but they had charged me 50 dollars and then my 2 yr daughter break it so soon. I thought of changing the main IC but it is glued with no name but thanks cheers!

Thank you for valuable information. I added one more pic of main PCB, can you please see and add more info to your already valuable answer