Lexicon 960L Service Manual page 20

960L Multi-Channel Digital Effects System Service Manual
3. Place the DMM ground lead on the Black wire connector and the DMM plus lead on the Yellow wire
connector and verify the is +12 VDC (± .6 VDC).
4. Place the DMM ground lead on the Black wire connector and the DMM plus lead on the Red wire
connector and verify the voltage is +5 VDC (± .25 VDC).
CD-ROM Drive Connector:
1. Locate the power connector on the back of CD-ROM drive.
2. With your DMM leads measure the voltages on the connector.
3. Place the DMM ground lead on the Black wire connector and the DMM plus lead on the Yellow wire
connector and verify the voltage is +12 VDC (± .6 VDC).
4. Place the DMM ground lead on the Black wire connector and the DMM plus lead on the Red wire
connector and verify the voltage is +5 VDC (± .25 VDC).
Hard Drive Connector:
1. Locate the power connector on the back of Hard Drive.
2. With your DMM leads measure the voltages on the connector.
3. Place the DMM ground lead on the Black wire connector and the DMM plus lead on the Yellow wire
connector and verify the voltage is +12 VDC (± .6 VDC).
4. Place the DMM ground lead on the Black wire connector and the DMM plus lead on the Red wire
connector and verify the voltage is +5 VDC (± .25 VDC).
For the following voltage tests, an I/O extender card (part # 023-14426) will be needed to bring the cards
out of the mainframe in order to gain access to the test points called out in the following tests.
Analog Output Card Voltage Test:
The supplies being tested on this card will be the +/-12 VSUP, and the +5VD provided by the main supply
via the backplane and voltages +5VD, 6.6V, +/-18V, 24V, and 36V created on the card.
1. Before powering on the 960L for this test, remove the Analog Output card from the rear of the chassis.
2. Insert the I/O extender card and install the Analog Output card into the extender card.
3. Power on the 960L.
4. For your ground reference locate test point marked GND to the Left of U3.
5. At the back right hand corner of the card locate the –12V-test point just below FB2. Verify the voltage is
-12VDC ±1.2VDC.
6. Next locate in the test point marked +12V just below FB3. Verify the voltage is +12VDC ±.6VDC.
7. Locate the +5VD voltage test point left side of the card just above U6. Verify the voltage is +5VDC
±.25VDC.
8. Locate the +5 VA voltage test point just below U3 between D8 and D9. Verify the voltage is +5VDC
±.25VDC.
9. Locate the + VB voltage test point on the right side of the card just to the left of C15. Verify the voltage
is between + 6.27 and + 6.93 VDC.
10. Locate the +/- VCC voltage test points on the right side of the card. +VCC is just to the right of C206
and –VCC is just to the right of that under FB54. Verify the voltage to be +17.50VCC and -17.50VCC
+/- 1.0 volt each.
Analog Input Card Voltage Test:
The supplies being tested on this card will be the +/- 12 VSUP provided by the main supply via the
backplane and the +5VD, and +5VA created on the card.
1. Before powering on the 960L for this test, remove the Analog Input card from the rear of the chassis.
2. Insert the I/O extender card and install the Analog Input card into the extender card.
3. Power on the 960L.
4. For your ground reference, locate test point marked GNDA just above D7.
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