Low Voltage; Overheating; Operational Problems - Lexicon PCM 91 - REV 1 User Manual

Troubleshooting
This chapter is intended primarily to help you recognize some
common error states which can be corrected from the PCM 91
front panel, or by simple means such as cable replacement. Any
error states which are not covered here should be referred to your
local dealer for service by a qualified technician.

LOW VOLTAGE

In a low-voltage, or "brown-out" condition, the PCM 91 will freeze
in its current state. None of the controls will have any effect. When
power returns to a normal level, the unit will reset itself as though
it had just been powered on. If the unit does not reset itself, turn
the power OFF, then ON to resume normal operation.

OVERHEATING

Temperature extremes may cause the PCM 91 to exhibit
unpredictable behavior. If the unit has been subjected to tempera-
tures below 32°F (0°C) or above 95°F (35°C), it should be turned
off and allowed to return to normal temperature before use. The
unit may be damaged by exposure to temperatures below -22°F
(-30°C) or above 167°F (75°C), or by exposure to humidity in
excess of 95%. If a unit exposed to such conditions fails to operate
after it returns to a normal operating temperature, contact your
local service representative.
COMMON MIDI PROBLEMS
The PCM 91 doesn't respond to MIDI Program Changes.
Check Receive control at Control mode 3.1 and make sure it is set
to On. Check the MIDI Channel selected as well as the MIDI
Channel of the transmitting device. Make sure that Pgm Change at
Control mode 3.3 is set to On.
connections between the units.
6-2
Also check MIDI In/Out
MIDI Program Change numbers are off by 1.
The PCM 91 transmits and recognizes ProgramChange messages
0-127. MIDI devices which transmit 1-128 rather than 0-127, will
be off by 1. Simply adjust by 1 when working with such devices.
The PCM 91 doesn't respond to SysEx commands.
Check the SysEx setting (and the Device ID selection) at Control
mode 3.7.
The PCM 91 does not transmit SysEx Automation commands.
Check the Automation setting (and the target device ID selection)
at Control mode 3.4.

OPERATIONAL PROBLEMS

The PCM 91 will not lock onto an incoming digital signal.
Check the cables that you are using. DO NOT USE ANALOG AUDIO
CABLE TO CONNECT DIGITAL AUDIO.
Also check to make sure that your input signal complies with
S/PDIF format standards. The PCM 91 will recognize AES
professional format signals from an appropriate connector, but will
not necessarily read and transmit encoded information accurately.
NO DIGITAL AUDIO OUTPUT
Check the Bypass state for any mute settings.
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