Imsai 8080 - Page 25

IMSAI 8080 System
General Assembly Motes
The board or the chip is very likely to be damaged if there
is a need to unsolder a chip that was soldered in with Pin 1
■ ^ in the wrong direction. Unless you are completely sure
you are capable of unsoldering an integrated circuit without
damage to the circuit or the board, you should send the
board back to the factory to have the work done for you.
Remember that on these boards with plated-through holes,
pins are not only soldered on the top where you see the
visible bead of solder, but is soldered inside the hole
which makes it much more difficult to remove.
Diodes
Diodes will typically have a band around the body, next to
the cathode end. This corresponds to the bar on the typical
diode symbol. The same is true for Zener diodes. A diode
symbol should be found on the board or assembly diagram to
indicate the proper mounting direction.
Capacitors
Some capacitors have a plus and minus lead; among them the
tantalum and power supply electrolytic capacitors. Some
mark on the body of the capacitor will indicate the plus
lead, typically a + sign near it. There will be a mark
(typically a + sign) on the board or assembly diagram to
indicate 'the proper direction to mount the capacitors. A
capacitor of this type is usually destroyed very quickly
if power is applied to it in the reverse direction, so check
your assembly carefully.
Transistors
Most transistors have a flat side or a small tab to indicate
the lead orientation. If this indication is oriented accord
ing to the assembly diagram the leads should fit in the holes
with little bending and no crossing.
25