Sequential PROPHET-600 - 1-3 POWER CONNECTION

1
SERVICE
1-0 PREPARATION
To ensure consistent performance, all instruments should be completely tested
periodically and preceeding any service or repair. This will uncover related or
unrelated malfunctions and provide a logical basis for troubleshooting. This section
contains all procedures needed to completely test a Prophet-600. In addition, the
scaling procedure and a few mechanical procedures are included. Functional tests
should proceed consistently in the order given. But to accomodate real-world
situations, each test is written so that it can be performed independently.
WARNING! You are responsible for the safe operation of this
instrument under service conditions. Incorrect grounding practices can
create lethal shocks. Scaling and other service operations must be
performed with power on. Under these circumstances lethal voltage is
present in the power supply primary area. Switch power off before
disconnecting or connecting any circuitry, or removing or installing
printed circuit boards (PCBs), integrated circuits (ICs), or other parts.
CAUTION! When operating disassembled, jumper the sleeve (ground) of
the AUDIO OUT jack to the chassis.
1. Check the Prophet-600 serial number. If it is 0001 through 0113, check that the
modifications described in paragraph 1-10 have been made. These modifications
correct problems of memory loss and sequencer malfunctions.
2. Only if the unit is "losing programs" while operating on 50 Hz power, check that
C308 (see Figure 1-4, page 1-13) is .02 uF.
3. Check the line voltage selector on the back panel and set as required.
4. Check that the fuse is correct for the selected line voltage:
U0V: 1/2A, slo-blo
220V: 1/4A. slo-blo
5. For easy monitoring simply plug standard stereo headphones (600 Ohm minimum
impedance) into the AUDIO OUT jack. Or if preferred, switch off power to monitor
system and connect AUDIO OUT to it.
6. Connect the CASSETTE IN and OUT jacks to the recorder (see Figure 1-0).
7. Connect the footswitch to the CONTROL FOOTSWITCH jack. (If an official
footswitch is not available, any normally-open switch which momentarily connects tip
to sleeve will work.)
TM600A 7/83
1-1