Step 18: Build Your Own Step 3 - Capacitors
More caution is required for the electrolytic capacitors (black cylinders in the pictures). First, there are two different values - 1uF (the group of four placed around the socket on the bottom left side), and 100uF (the other four). Second, those capacitors are polarized - inserting them the wrong way around will destroy them when you power up the scope. The silkscreen indicates the positive side (with a "+"), as is usual practice. Strangely enough, the capacitors themselves have the negative side labeled (with a "-", the vertical gray stripe on the capacitors), so make sure you put them in the right way.