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Install the IC’s and Transistor
Make sure to orient the IC’s correctly when you install them. After you install each IC,
bend over two diagonally opposed leads to retain the IC. Then double check to make sure
that:
You have the correct IC in the correct location.
The IC is oriented correctly.
Figure 21-Insert all the IC’s so that the U-shaped indent matches the silk-screen
Integrated Circuits
Designation Value
Description
Done
U2
74HC595
8 bit serial in parallel out shift register
U3
74HC595
8 bit serial in parallel out shift register
U6
74HCT04 Hex inverter
U7
74HC166
8 bit parallel in serial out shift register
U8
74HC166
8 bit parallel in serial out shift register
Caution: Don’t confuse U5 and Q1. They are both in very similar looking TO-92
packages. Look carefully at their markings.
Regulator and Transistor
U5
LP2950
3.3 volt regulator, TO-92 package,
marked KY5033
Q1
2N3904
NPN transistor
1
, TO-92 package
Install the Resistor Networks
Designation Value
Description
Done
RN1
8 10K
resistors
Install RN1 in the indicated place. Make sure that
pin 1 of RN1, marked by the dot, goes into pin 1 of
the RN1 hole pattern on the PCB, indicated by a
square pad on the PCB. Solder the two end pins
first to make sure that RN1 is sitting level on the
board. Once RN1 is level, solder the balance of the
1
Early versions of the kit used MPSA06 transistors.
