DISCO DAD 2H/6T, Troubleshooting Manual

Page: 103 / 186

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WHAT AND HOW TO CHECK REMEDIAL ACTION
7-1. (1) Take out fuses F1 and F2 in the P.C. board and
check them with a tester.
7-1. (1) If they have blown, replace the fuses. Also
investigate why the fuse has blown. If they have not
blown, check other parts.
(2) Check the voltage of the Power Supplies with a
tester (synchroscope). Across the Tantalum
Capacitor C21:
+5V
±
0.25V
Across the chemical-Capacitor C33:
+10V (10V-15V)
At the Exchange Terminal of Diode 21:
AC 50V (AC 45V-55V)
(2) If the values of voltage are not correct, check and
repair as necessary, the transformer and PB17
(EAUA--024500). If they are correct, check other
parts.
(3) Check the waveforms of each output with a
synchroscope. Refer to figures (on pages 26 and
27). (Fig. 2 and 3)
(3) If normal waveforms as shown in the figures are
obtained, the board would seem to be normal; check
other parts. If not, replace the board or other
defective parts.
Note: When the connecting cable is opencircuited,
the output waveforms are out of order.
7-2. (1) Same as in 7-1 (3). 7-2. (1) Same as in 7-1 (3).
7-3. (1) Same as in 7-1 (3). 7-3. (1) Same as in 7-1 (3).
(2) Check the PB numbers and body numbers of the
P.C. boards.
(2) If boards are mounted the wrong way, reset them.
(3) Turn off the power and rotate the motor by hand to
check the load.
(3) Investigate the mechanics if the load is too heavy.
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