ENSONIQ Mirage - Page 3

Servicing the Mirage is quite simple and straightforward. Rather than diagnose and replace individual components, you will replace complete
modules.
The
Ensoniq
Module
Exchange
Program
is
available
to
all
Authorized
Repair
Stations
and
will
be
the
most
cost
and
time
efficient
method
for both you and your customer.
At Ensoniq we are equipped with sophisticated machinery to diagnose module faults quickly and accurately. The exchange program will help you to
make reliable repairs to your customers’ instruments with a minimum of downtime and expense.
The troubleshooting chart will cover just about any occurrence and will tell you which module should be replaced. Refer to the appropriate section
for the steps involved in the replacement of the particular module.
TROUBLESHOOTING THE MIRAGE
Most problems with the Mirage will be fairly easy to diagnose, with a few exceptions. What may appear to be disk drive or display problems are
often problems with the power supply or with a defective diskette. For this reason, we recommend that you always load a diskette that you know is
good and check the power supply before troubleshooting the rest of the unit.
TO CHECK THE POWER SUPPLY
First, plug the Mirage in and turn it on. Then remove the five screws securing the control panel and raise the panel. Check to make sure that all the
connections are secure and correct.
When the Mirage has warmed up for five minutes begin to test the voltages at the points shown in Figure 2 and Figure 3A - 3B. If the voltages vary
outside the allowable limits, replace the power supply and test the unit before proceeding with further diagnosis.
TRANSFORMER AND POWER SUPPLY VOLTAGE CHECK POINTS
The following charts show the connector terminal number and correct voltage values for the power supply and transformer.
POWER SUPPLY VOLTAGE MEASUREMENTS
MEASURE BETWEEN
VOLTAGE VALUE TERMINAL NO.'S
REAR OF UNIT f
N A
+5VDC +5%
(SOmv AC ripple max.)
TO HARNESS
+12VDC +10% POWER SUPPLY BOARD
(100mv AC ripple max.)
L
TO HARNESS Ба
-12VDC
+10%
TO
TRANSFORMER
(100mv AC ripple max.)
FIGURE 2 - POWER SUPPLY VOLTAGE CHECK POINTS
ISVAC +20%
24VAC +20%
AC LINE VOLTAGE MEASUREMENTS
REAR OF UNIT t With the power switch OFF, 120VAC should
measure from:
ІА - 2A
2A - 2B
3A - 3B
FUSE
BOTTOM HOLDER
FIGURE
3A
IS
INCORRECT
Refer
to
Service
Bulletin
#5
for
AC
Line
Voltage
Check
Points
With the power switch ON, 120VAC should
measure from:
| i T 1A - 2B
SMALL CONNECTOR | ІВ - 2B
2B - 3A
NOTE: LOAD SIDE MUST BE FUSED 2B - 3B
There should be no voltage across the
power switch contacts (3A - 3B).
WIRE WITH LARGE CONNECTOR
FIGURE ЗА — AC LINE VOLTAGE CHECK POINTS
WIRING FOR EARLY MODEL CASE (WHERE TRANSFORMER IS ON THE LEFT).