There are five transistors supplied. Four of them are PNP type BC558, and one
is an NPN BC547. Do not mix them up and mount them as shown on the PCB
overlay.
Now solder the 9 pin RS232 socket, the USB socket and the power jack on to
the board followed by the 7805 and 78L08 regulators, again carefully checking
orientation.
The next parts to mount are the 2 crystals. One is a 4MHz type and the other is a
6MHz so don't get them mixed up.
You can now mount the DPDT switch and the ZIF socket.
There is 1 wire link that needs to be fitted to the board. DO NOT insert it at this
stage.
The last things to fit to the board are the rubber feet. These stick to the
underside of the PCB, one in each corner.
Now you should go over all of your work and inspect for dry or unsoldered joints
and check all components for correct orientation and placement.
If you are satisfied that all is well, then you will need an 18VDC power supply to
test the board. Positive should be on the inner connection of the power jack as
shown on the PCB overlay.
Connect the power and observe that
the power LED (L4) lights. If not,
turn off the power immediately and
check the orientation of diode D2 nd
the power wiring. Re-check the PCB
for any other mistakes.
Turn the power back off if the LED
did light up. Make sure you have a
multimeter ready for use and set it to
measure 5 volts DC. Turn the PCB
back on and measure the voltage
between a test pads marked on the
PCB (+5V) and (Gnd) near the
RS232 socket.
The meter should read close to 5 volts. If not, turn off the power immediately and
check that the regulators are inserted properly.
