thickness control knob has a direct effect on the printer’s phasing (which has to do with the quality of the printed character). For this reason, it is important that this be set properly. Once you become familiar with the various buttons, levers, and controls of anyone of the many printers you may  be  working  on,  you  will  quickly  find  that  most forms are relatively easy to align. For those that are not, such  as  preprinted  forms,  often  the  programmer  will assist you by printing out form alignment characters to allow  for  proper  alignment  before  the  actual  printing  of the job. OPERATOR   MAINTENANCE.—   Although  a maintenance contract is usually carried on the printer, you   are   still   responsible   for   part   of   the   routine maintenance. Keep  the  exterior  and  interior  of  the machine  clean  using  a  vacuum  cleaner  wherever possible. Check the print mechanism for carbon and ink buildup   that   accumulates   and   eventually   causes problems.  And  most  importantly  of  all,  change  the printer ribbon as often as needed. When the print starts to fade and adjustments to the form’s thickness and print density controls do not seem to help, then it is time to change the printer ribbon. It   is   a   good   practice   to   get   into   the   habit   of performing a test print before starting a job, especially if the job is a lengthy one. A test print is a routine designed to show you whether the printer is functioning properly: that  each  and  every  character  is  clear  and  sharp  (not chopped  or  halved),  that  all  characters  are  uniform throughout the entire print line (not wavy), and that all print hammers are firing properly. You should now have a basic understanding of, how to remove, load, and align forms in the printer; setup the required print controls; be able to respond to the various machine   indicators;   and   perform   routine   operator maintenance functions. Reduce File Fragmentation File fragmentation occurs when you delete a file, leaving, basically, a hole in the information on the hard disk, or when you add information to an existing file when there is no contiguous space left next to the file. To  correct  fragmentation,  you  can  make  a  backup, reformat the hard disk, and restore your files. You can also   run   a   software   program   referred   to   as   a defragmenter to reorganize the files so the data in each file  is  contiguous. 2-34 Troubleshooting and Isolating Problems Problems  will  range  from  simple  to  disastrous.  The printer may not be printing because it is out of paper. The disk drive may not be reading because the drive latch is not closed. The printer maybe printing garbage because  the  incorrect  printer  definition  is  used.  The hard  drive  may  be  having  excessive  read  errors.  The problems   may   be   operator/user   errors,   software problems,   or   hardware   malfunctions.   Knowing which  is  sometimes  easy.  Under  other  conditions,  it may be difficult to determine the source of the problem. TROUBLESHOOTING.— Learn about common problems.   For   example,   what   does   it   mean   if   the monitor  screen  goes  blank?  Is  the  problem  a  simple one, such as the monitor has an automatic function that turns  off  the  screen  when  it  hasn’t  been  used  in  a specified   amount   of   time?   Pressing   any   key   will reactivate the screen. Or, have the brightness or contrast thumbwheels been turned, causing the screen to look blank? A turn of a thumbwheel may bring the monitor screen back to light. Has a cable become disconnected? Has the power been turned off? Is the monitor or power strip  unplugged?  Or,  is  the  power  supply  no  longer working? Has the operator hit a combination of keys by mistake that has caused the screen to go blank except for the status lines? Look at the status lines to see if they provide  information. Whatever  the  symptoms,  look first  for  simple  logical  answers.  Check  all  cable  and outlet connections. Check to see that each component of the system is plugged in properly. Check to see that the  proper  options  are  selected.  For  example,  on  the printer,  is  it  in  a  ready  status?  Are  the  proper  dip switches set? Is the printer out of paper? Is the correct mode of operation selected, either through the buttons on the printer or through software? If the software and hardware allow using several printers, is the correct one selected, and are any manual selections made when a switch  box  is  used? We could go on and on with examples. The point is, learn  from  experience. Keep  a  list  of  symptoms, probable  causes,  and  ways  you  can  use  to  trace  a problem to its cause. This will help you to diagnose and troubleshoot  problems. You  will  find  users  tend  to make the same mistakes over and over, especially while learning.  Help  them  by  telling  them  about  common problems,  the  reasons  for  the  problems,  and  ways  to avoid having them happen to them. You  will  soon  learn  the  common  errors,  keep  a mental list of the sequence you use to start isolating a problem.  You  may  want  to  develop  a  checklist.  For