G E N E R A L - Philips SPENDEX 40 Maintenance Manual

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NATO CONFIDENTIAL
S P E N D E X 4 0 U A 8 2 5 1 / 0 0 A N D / O l L I M I T E D M A I N T E N A N C E M A N U A L
6 FAULT FINDING AND REPAIR PROCEDURES
6 . 1 G e n e r a l
This chapter gives a full description of the fault finding and repair
procedure, which can be performed when a SPENDEX 40 does not function
or does not function properly. The described fault finding and repair
procedure is restricted to:
- the location of a defective module;
- the replacement of this module;
- the performance of a functional final test.
The location of the defective module can take place on the basis of
the fault finding diagram of Fig. 6.1, Fig. 6.2 and Fig. 6.3. In the
fault finding procedure laid down in this diagram use is made of,
among other things, the failures detected during the initial
self-test and the set-up test. The self-test automatically starts
after the switching on of the equipment, whereas the set-up test has
to be carried out by the operator. The set-up test only makes sense,
when no failures have been detected during the self-test.
As soon as a defective module has been located, it must be replaced.
Before replacing a module check any possible hardware settings and
see to it that the settings on the replacing module correspond to
those on the module to be replaced. For detailed demounting and
mounting instructions see chapter 7.
After one or more modules have been replaced, a functional final test
should be carried out to check whether the equipment does function
— i p r o p e r l y a g a i n . T h i s f u n c t i o n a l f i n a l t e s t c o n s i s t s o f t h e c a r r y i n g
out again of the self-test and the set-up test.
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6 . 2 S e l f - t e s t
After being switched on the equipment starts an initiation procedure
followed by an automatic self-test. During this self-test various
c i r c u i t s a r e t e s t e d o n t h e i r f a u l t l e s s f u n c t i o n i n g , v i z .
- program memory 1 (main-EPROM)
- program memory 2 (user-EPROM)
- the data memory black
- the data memory red
- the zeroise memory
- t h e i n t e r r u p t c i r c u i t
- the time base
- timer long and timer short
- the key generators (PKG, CKG and RKG)
- the modem
I f n o e r r o r s a r e d e t e c t e d " * " a p p e a r s i n t h e d i s p l a y a f t e r
some seconds and the equipment is ready for operation. If an error is
found, this will result in a fatal or non-fatal hardware alarm. An
error will result in a fatal hardware alarm when as a consequence of
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