TM 32-5835-001-24 & P
in this manual will
on functional circuits
within the recorder or power supply. To enable effective troubleshooting three types
of information are available in this manual.
Principles of Operation
c. Parts Location Diagrams
Principles of operation is a brief description of how each functional circuit operates.
The schematic diagrams employ a two level test point system:
a. Numbered Star.
Locates test points necessary to isolate a malfunction to the
b. Lettered Circle. Locates test points necessary to isolate to the defective stage
within an assembly. The parts location diagram physically locates all the test points
identified on the schematic diagram in addition to the associated assemblies and parts.
The selection of the physical test point locations was made to minimize access time and
eliminate disassembly which thereby reduces technician repair time and equipment
down time. The parts location diagram also includes applicable quiescent voltages on
the pins of active devices to aid in troubleshooting within the stage to the defective
piece part; pin location diagrams and test conditions are also included. A Maintenance
Action Precise Symptom List (paragraph 3-5) assists technicians to accurately trouble-
shoot a recorder set when the fault symptom has been identified.
Before performing troubleshooting procedures on the recorder,
clean and demagnetize the audio head.
a. General. Occasionally the audio and erase heads may become permanently mag-
netized through improper use of the equipment or by contact with magnetized objects.
Magnetized heads may cause an increase in distortion and can impair good recordings
by partially erasing high frequencies.
Set Mode selector to OFF.
Open cassette loading door and remove cassette.
Plug demagnetizer into 117 Vac source.
If tips of demagnetizer are uncoated (plastic) , place one layer
of electrical friction tape on the demagnetizer tips to prevent
scratching of the heads.