Grandpa asks you to get the pliers.
On top of the machine is a toolbox. Climb the ladder and search the toolbox to get the pliers out. But then they hit the lever. The world is upside down. Pull the lever to see if you can reverse it.
Move the ladder two times and climb the ladder to get the PLIERS. Climb down the ladder and use the pliers on the lamp on the left to clear your path. Examine the bookshelf on the left. Keep examining until you find the BOOK about the gravity inverter and read about the machine. In chapter three you’ll read about the calibration.
Move the ladder on the right twice again and climb the ladder. Use the pliers on the lamp to get the BULB out. Climb down the ladder again and use the panel on the machine to see what’s inside. There’s a bulb missing so insert the light bulb in the hole on the right.
Now you need to make them burn all bright. Number them from 1 to 4 from left to right and push the button 4 twice, button 2 twice and button 1 twice. The lights are all bright now. Pull the lever again and everything will be back to normal.
Game source: A copy of the game was found here on the internet.