unplug  it.    Do  not  attempt  to  repair  calculators yourself.  All repairs and maintenance should be done by qualified technicians or company representatives. Because it is solid-state, the electronic calculator needs little  maintenance.    Ensure  all  electrical  equipment aboard Navy ships comply with all safety regulations. TYPEWRITERS Your typewriter may be heavy and rugged looking, but it is really a delicate instrument.  Treat it like one and  give  it  daily  care.    A  machine  in  first  class condition is easier and quicker to operate and turns out professional looking work. Observe the following routine procedures: Be sure the typewriter is properly placed on the desk, or secured to the well type of desk, so it will not  fall.    Aboard  ship,  it  should  always  be secured. In lifting a typewriter, grip it by its case, NEVER by its carriage. Keep your typewriter covered when not in use. Always cover it or close it into the desk at the end of the day. Keep it clean, wiping the outside with a soft dry cloth and dusting the inside with a long-handled brush. At regular intervals you should give the typewriter a  more  thorough  cleaning.    Frequency  of  these cleanings  will  depend  on  the  amount  of  use  the typewriter receives and the amount of dust in the air in your  office.   In  general,  it  is  recommended  that  the following procedures be carried out weekly: Clean the carriage rails and marginal stop bar, using a cloth slightly moistened with lubricating oil.   Move  the  carriage  back  and  forth  in  the process. Clean the cylinder or roller.  Remove if possible and  wipe  with  a  cloth  moistened  with  a  very small amount of denatured alcohol or cleaning fluid. Do not wipe off; allow fluid to evaporate. Dust  the  interior  of  the  machine.    Use  a long-handled brush, brushing toward the front of the machine. Wipe the sides and back of the machine. If  operating  instructions  for  your  typewriter  are available, they will help you identify parts and give you additional information. If  further  oiling  or  repair  work  is  needed,  the machine  should  be  turned  over  to  a  qualified repairman. COMPUTERS The  world  is  constantly  changing.    Using computers  has  changed  the  way  business  is  done. Today’s  Navy  operates  through  the  use  of  modern state-of-the-art weapons and computer systems.  New computer technology has had a tremendous impact on the efficiency of operation, and as a PC, you will be able to accomplish more by using a computer. Because of  this  advanced  computer  technology,  as  the publications and forms used in a post office become more  available  in  computer  format,  administrative jobs that used to take a long time to accomplish can be done rapidly and more easily. Not all Navy post offices have computers, but they are becoming more common. Q3-30.   What   determines   the   type   of   post   office equipment that will be placed in your MPO? Q3-31.   How  often  must  scales  that  are  used  at  the finance window be checked for accuracy? Q3-32.   What  publication  must  be  referred  to  when postage rate charts are ordered for automatic computing scales? Now turn to appendix 1 to check your answers. 3-21