Sharp MZ-5500 User Manual

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MZ-5600
(2)
Checking the trouble cause
Check procedure
Trouble phenomenon
Oefective
location
(START)
1-1. Check
the + 12 V output. Check that;
+12V output load is 0.5A.
+5V is free load.
-12V is free load.
1-2.
Connect
the oscilloscope
Set
the oscilloscope to 1 V /div, 5J,Ls/div.
to M2 -5 pin.
2-1.
Slowly increase the input
Turn input
OFF if the input current
RC1, RC2, 03, 04, 06, 07,04,
voltage.
should
exceed 1 A when it is increased
07, 08, C3, C20.
to 10V.
(012) applies to 01.
3-1.
Check if a triangle waveform
Make sure
that it is as shown below.
M1, M2, C5, C25, F1
is observed. If no, replace
the parts. Otherwise, go to
~3
•
4-1.
~
4-1.
While observing the wave- Connect oscilloscope probes to 06 and
05,06,07, M1, M2, 06.
form between 06 and VCE, VCE and make sure that the waveform (012,010) applies to 01.
increase the input voltage. appears as shown below.
1JL~
~
14
I 28V
.·20I'sec.
5-1.
Confirm appearance
of
Adjust the + 12V output voltage by means
M2, 011, VR2, R36, (012, 010)
+12V output voltage. of VR2. Clockwise turn of the VR2
applies to 01.
increases the voltage. Short current of
;
+12V is 1A.
6-1.
Check +5V output_ Check that:
+5V output has a load of 0_2A.
+12V output is free load_
-12V output is free load.
6-2.
Increase input voltage by Connect the oscilloscope and observe the
M1, 04, 05, 04, 05, C9, C10.
;
observing the waveform
waveform between
03 and VCE.
between 03 and VCE.
(See Item
4.)
Adjust
the input voltage to 22V.
Check if oscillating_ If no,
replace the parts.
If yes, go to 7.
t,
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tr

Sharp MZ-5500 Specifications

General

Brand	Sharp
Model	MZ-5500
Category	Desktop
Language	English