ARMY  TM  5-6675-238-14 MARINE CORPS TM 08839A-14/1 a. b. c. d. e. f. g. h. Do  not  use  sharp  tools  or  volatile  sol- vents. Avoid excessive pressure on glass. Failure to comply may result in damage to equipment. Open  lamp  assembly  cover. Using a dry strip of clean, lint-free cloth, wipe the two glass surfaces and surrounding area of head. NOTE If  glass  cannot  be  cleaned  thoroughly with  a  dry  lint-free  cloth,  proceed  with steps c thru g. Prepare a cleaning solution of water and mild liquid   detergent. Wipe glass surfaces with clean, lint-free cloth moistened with cleaning solution. Use cleaning solution sparingly and do not saturate area. Rinse area with clean, lint-free cloth moistened with clean water. Wipe dry with clean, lint-free cloth. Inspect  glass  surfaces  for  cleanliness  making certain  that  no  residue  is  present.  If  further cleaning is required, repeat steps c thru g. Close  lamp  assembly  cover. 8-44.1. Tape Reader, Part No. 877406-2, Head Clean- ing. The glass surfaces of the tape reader head must be cleaned  to  prevent  excessive  accumulation  of  dirt. Clean the tape reader head as follows: a. b. NOTE A cleaning kit part no. PL20598 is availa- ble from Decitek Corp. (33275). This kit consists  of  a  brush  and  rectangular  strips of lint-free plastic wiper material. Use the brush to remove visible dust from both inside and outside the tape reader cover housing. Trichloroethane 1,1,1-stabilized is toxic and caustic. Use only in a well-ventilated area and avoid physical contact. Saturate approximately one inch of the center of a plastic wiper strip with trichloroethane 1,1,1- stabilized. c. d. e. f. g. h. 8-45. Stretch  the  plastic  wiper  strip  to  decrease  its thickness so that it fits between the phototransis- tor array and the fiber optic termination plate. Decrease the stretch to a point where the plastic wiper  strip  contacts  the  upper  and  lower  sur- faces with a wiping action. Move the plastic wiper strip back and forth in the direction of tape travel approximately 30 to 40  passes.  Movement  should  be  relatively  easy.  If movement is difficult, stretch the plastic wiper strip a little more. Remove plastic wiper strip and inspect for exces- sive dirt. Saturate  the  center  section  of  another  plastic wiper  strip  with  trichloroethane  1,1,1-stabilized. Stretch strip and insert and move back and forth for  approximately  10  to  20  passes. Remove  plastic  wiper  strip  and  inspect  it  for dirt. If no dirt has been collected, consider the tape reader head clean. If dirt is evident, repeat step g until clean. Self-Test,  Operational,  and  Diagnostic  Tape Cleaning Using Tape Reader, Part No. 877406-1. a. Connect tape reader to SPU as shown in figure 8-2. b.   Set   tape   reader   SPOOLING   switch   to   DIS- ABLE. c.  Place  tape  reel  on  left  tape  reader  spindle  and lock  in  place. d.  Unwind  about  four  feet  of  leader,  then  thread tape around tape guides and tension arms. Manu- ally wind a portion of the tape onto take-up reel. Do not thread tape through tape head. e. Press SPU ON switch-indicator to on, f. Set tape reader SPOOLING switch to ENABLE. Isopropyl  alcohol  is  flammable  and  gives off harmful vapors. Use only in well-ven- tilated area away from open flames and sparks. Avoid prolonged or repeated inha- lation  of  vapors. NOTE If  the  tape  is  excessively  dirty,  several cleaning cycles (steps g thru i) should be made, the first with the cloth moistened with  isopropyl  alcohol. Change 1 8-105