Okay, so, I don't know about a walk through, but I had the same problem. You've got to search the whole house. I had to restart but after thinking about it. I wonder if you had to click on all the weirdly shaped lamps in the bathroom and bedroom.
There is no walkthrough, as the quest log is quite self-explanatory. Anyway, here is a step-by step guide to chapter 2:
TUCKER'S PDA
Go to school, to the left corridor. Tucker will ask you to retrieve his PDA from the girls' locker room.
The room is in the right corridor. Dash in front of the door and will not let you enter, unless you accept to provide him with a pair of your sister's panties. You can:
a) tell him to fuck off. He will beat the crap out of you, but then you will be able to access the locker room AND you will get a nice scene with nurse Kate.
b) accept. You must wait for the afternoon, go home and enter Jazz's room. On the bed you can find a pair of panties. Give them to Dash the next day to enter the locker room. This also unlocks Star and Kwan's scene.
After you retrieve the PDA Dash will be possessed by Ectopuss and assault Jazz. Defeat it then go to Tucker and give him his PDA. He will give it to you as a gift. Now you can add people's numbers and chat with them. Every character is online in a different time of day or night. This completes the TUCKER'S PDA quest.
IN HOT WATER
While you are at home in the afternoon, you can also a peek at your sister in the bathroom (using the spare key; if you already entered her room, it's in the drawer near the bed). She will be attacked by Ectopuss. Defeat it. This completes the IN HOT WATER quest).
WE NEED TO TALK
- Go to School. Sam will ask you to meet her at night at the park
- If you meet with Sam, Ectopuss will appear and you will have to fight it. After that, you will go home and meet Vlad Masters. He will show his Thermos to your parents, releasing another Ectopuss. You can choose to let it assault Maddie (unlocking a scene) or save your mom. This completes the WE NEED TO TALK quest and ends chapter 2
PLEASE REMEMBER TO UPGRADE DANNY'S STATS WHEN HE LEVELS UP (CLICK ON THE SMALL PORTRAIT ON THE TOP LEFT)
Have fun!