Now  you  can  solder  the  diodes  D3  to  D4  in  place  observing
their  orientation.  The  cathode  is  the  end  with  the  line  marked
on the component. Mount  resistor  R33  next  but  leave  it  raised  off  the  PCB  surface  by  a  few
millimeters so that air can circulate around it. Mount  the  crystal  next.  You  need  to  take  care  that  the  crystal  case  does  not
short the tracks beneath it after it is mounted on the PCB. To avoid this use one
of  the  diode  pigtails  (offcuts)  and  place  it  under  the  crystal  before  placing  the
crystal in it’s mounting holes. Solder the crystal in place, avoiding excess heat,
and  then  remove  the  pigtail.  There  should  now  be  a  small  air  gap  under  the
crystal. After soldering them check the connections under a strong light and make sure
there  are  no  shorts  between  the  pins.  Bear  in  mind  that  some  pins  may  be
shorted on the PCB design which is OK. Solder in the IC sockets for U7 and U8 next. Now solder the electrolytic capacitors C7, C8, C11, C12, C13 and C14 making
sure you observe the polarity of each component. The 1uF caps near U8 may
need to be bent slightly forward before soldering to make sure they fit under the
LCD. Damage will be caused if these components are mounted the wrong way
around.  The  negative  pin  has  a  stripe  marked  on  the  side  of  the  component
case. The PCB overlay highlights which pin is positive with a small plus (+) sign.
Capacitor  C1  is  a  tantallum  type  and  it  must  be  inserted  correctly  or  it  will
probably fail very quickly. The positive terminal will be marked with a small (+)
sign. Next you can mount the 4 transistors but make sure they are inserted correctly.
They all look the same, but they are different devices. These can be followed by
the  2  LEDs.  The  anodes  are  the  longer  of  the  two  connection  leads  and  the
cathode is marked with a flat surface on the LED body.