SECTION 6
TROU BLESHOOTI NG
A . GENERA L
This s ection provides information about Oltronix regulated power supplies ,
type RAC PAC 150, 300, 600 and 1000 that will enable
an
efficient trouble
shooting in case of equipment failure.
Before troubleshooting the power supply, study the rest of this instruction
manual,
·
especially s ection 4 " Circuit Description' ' in order to b ecom e fami
liar with the principles of operation.
We have not attempted to give a complete detailed step-by-step instruction
for finding the cause of all possible troubles .
This guide rather gives a check schedule that leads the fastest way to detect
the most probable area of the actual trouble.
If a burned component is found, special care has to b e taken . This kind of
fault often indicates that there is another fault in the circuit as well . Be
sure to find out wat has caus ed the component to burn b efore it is replac ed.
B efore starting a detailed troubleshooting, m ake sure that an apparent troubl e
is due to malfunction within the power supply and not due to improper control
s etting, Initial check instructions are give in this s ection, paragraph C .
B . PROCEDURE TO GUIDE TROUB LESHOOTING
E quipm ent needed: D C voltmeter, AC voltm eter, oscillos cope.
The troubleshooting pattern is divided into three parts .
Always start with "Initial checks" . If the fault
still
remains locate the faulty
::irea with the " Fault area location table" . Then proc eed the troubl eshooting
according to the given table .
The values indicated in the tables are typical values which vary slightly from
instrument to instrument. Some of the readings are al so depending on the
line voltage . If th e line voltage is more than a few perc ent off its nominal
value, us e a variac and adjust it for correct voltage .
If a transistor has been replaced, consult table 8 for necessary calibrations .
C , INITIAL CHECKS
a. "Sens e switch in "!NT" position.
b. S4 on main PC-board in "NORMA L.' ' position.
c . OVP off (=fully CW) .
d . Check line and OVP fus es . The former on the front panel, the latter on
right hand side with RAC PAC 150
& 300
and on the rear with RAC PAC
600
&
1000 .
Note: If the OV P fus e F2 is blown, this usually indicates a fault in the vol
tage stabilizing circuits .
e . Check that the transformer is wired for proper line voltage ( s ee instruc
tions on the transformer) .
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