LEGO Harry Potter: Years 1-4

Here's a link to a guide I made. It has the location of every collectable in the game, including all the Red Bricks.

http://www.xbox360achievements.org/forum/showthread.php?t=24...

To make things easier, you'll want to grab the Red Brick Detector first. Either use the cheat (7AD7HE) or you can find it in the Library Second Room (see the above guide). You'll still need to find the red brick eventually in order to get 100%. You can buy the Red Brick extras from the upstairs of Eelops Owl Emporium in Diagon Alley, after you have unlocked them by finding them/getting them delivered by an owl.

**Please leave a comment/message me if you vote negative or see an error, I'll try to help :)**

~IF YOU WANT TO BE A CHEATY McCHEATERTON (like me ):

Enter these cheats (Once the Leaky Cauldron hub area has been unlocked, enter Wiseacres Wizarding Supplies in Diagon Alley. Go upstairs, talk to the vendor. From there you can enter the cheat codes.):

Carrot Wands AUC8EH
Character Studs H27KGC
Character Token Detector HA79V8
Christmas T7PVVN
Disguise 4DMK2R
Extra Hearts J9U6Z9
Fall Rescue ZEX7MV
Fast Dig Z9BFAD
Fast Magic FA3GQA
Gold Brick Detector 84QNQN
Hogwarts Crest Detector TTMC6D
Ice Rink F88VUW
Invincibility QQWC6B
Red Brick Detector 7AD7HE
Regenerate Hearts 89ML2W
Score x2 74YKR7
Score x4 J3WHNK
Score x6 XK9ANE
Score x8 HUFV2H
Score x10 H8X69Y
Silhouttes HZBVX7
Singing Mandrake BMEU6X
Stud Magnet 67FKWZ

Then, go get the one you'll be missing (#18) in the courtyard (with the pendulum... the area the ghost goes through a lot). Destroy the statues around the water and then build the pieces. Turn the red brick in to the bird toward the back.

Achievement unlocked!

EDIT: I did NOT need to actually collect any red bricks besides #18 to get the 100% achievement.

# AUC8EH - Carrot Wands
# H27KGC - Character Studs
# HA79V8 - Character Token Detector
# T7PVVN - Christmas
# 4DMK2R - Disguise
# J9U6Z9 - Extra Hearts
# ZEX7MV - Fall Rescue
# Z9BFAD - Fast Dig
# FA3GQA - Fast Magic
# 84QNQN - Gold Brick Detector
# TTMC6D - Hogwarts Crest Detector
# F88VUW - Ice Rink
# QQWC6B - Invincibility
# 7AD7HE - Red Brick Detector
# 89ML2W - Regenerate Hearts
# H8X69Y - Score x10
# 74YKR7 - Score x2
# J3WHNK - Score x4
# XK9ANE - Score x6
# HUFV2H - Score x8
# HZBVX7 - Silhouttes
# BMEU6X - Singing Mandrake
# 67FKWZ - Stud Magnet

Now for the last red brick. you must go to the courtyard with the fountain and use leviosa on the fountain and then the last red brick will be unveiled. take it to Hedwig at the back of the yard and she will take it and 45G will be yours.

EDIT: You may still need to collect the bricks normally to get the 100% achievement but this solution allows you to get the achievement more quickly.