Sequential Pro One - Preparation

SECTlON 1
FUNCTIONAL TESTS
1-0 INTRODUCTION
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This section contains procedures for complete functional testing of the Pro-One. The
functional tests check all signal paths and the range of the oscillators. A flow-chart
for selectively checking tuning- is on page 1-12. To correct oscillator tuning, see the
Service procedures in Section 5.
Instruments to be serviced should be completely tested beforehand. This will reveal
related or unrelated malfunctions, and provide a basis for troubleshooting, If a trim
can't
be achieved service will: certainly be required. In such cases, consult the theory
of operation and diagrams in Section 2, and schematics in Section 3 to isolate the
failure.
Mechanical procedures are in Section 4. When operating disassembled it can be
difficult to read the controls: Figure 3-1 may be of help. Also, when disassembled it is
often convenient to leave the wheel cable disconnected. The Pro-One will operate
normally, that is, without pitch bend or modulation.
These procedures are presented in the order recommended for a Pro-One assumed to
be completely operational. Real-world problems may require you change the order of
some tests. Therefore each is written to be performed independently.
You must play the Pro-One throughout these tests (or use the ascending and
descending scales preprograrnrned into SEQ 1 and SEQ 2 on power-up). All tests are
performed by ear, the object generally being that the
knobs adjust smoothly and
switches work. Toggle the panel switches repeatedly to check for intermittents.
1-1 PREPARATION
I. Connect headphones, or mono cable between back panel AUDIO OUT jack and power
amplifier,
2. Check back panel 1 14/23O line voltage selector.
3. Check that back panel power switch is off.
4. Ef operating disassembled, testing may be facilitated by placing the knobs lightly
back on their shafts..
5. Connect power cable to properly-grounded outlet.
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6. Switch power on. ,J
WARNING! LETHAL VOLTAGE IS PRUENT IN THE POWER SUPPLY AREA
OW THE PCB (IN EARLIER MODELS) OR ON THE BACK PANEL (IN LASER MODELS).