In the Legend of Zelda: Breath of The Wild, you can upgrade the Sheikah Slate by completing the Locked Mementos Quest. In order to take on the quest, you need to go to the Kakariko Village and get the quest from Impa. Then you need to get to the research lab in the Hateno Village to upgrade Sheikah Slate. The following guide shows how to complete the Locked Mementos quest and upgrade the Sheikah Slate in the game.
Complete Locked Mementos Quest and Upgrade Sheikah Slate:
After taking on the quest, follow the road of east when you see a road split and you will reach Fort Hateno. You can also use the horse to reach fast. After reaching the Fort, continue to follow the path ahead and when you come across a fork in the road, take the left path to reach the Hateno Village by passing through many enemies. When you are inside the village, go up around, on the cliff you will find the Hateno Ancient Tech Lab.
In the Lab you will meet a girl named Purah, who will direct you to the director Symin. When you go and talk to Symin, he says that Slate is missing the basic ruin and in sometime you will find out that he is not the in charge of the Lab and Purah is the director of the Lab. She will accept to repair the Slate if you bring her the blue flames from the ancient furnace in the Town.
The blue flame is needed to light up the furnace in the Lab. Find the blue flame from the ancient furnace by torching from lamp to lamp, when you reach the lab, light up the furnace outside the lab with blue flames and gate will be activated, get inside the Lab and talk to Purah, she will repair your Sheikah Slate. You will also get an Album, Hyrule Compendium and Camera as rewards.
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