Onkyo TX SV919 Service Manual

ONKYO USA CORPORATIO N

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Date: 10/02/99
Ref #: SV919VOL

Title: TX-SV919
Symptom: No audio, Volume control does not make any change on display, unit does turn on and

stay on.

Solution: 5 volt to volume control needs restoring.

Classification: Service Ti

Volume control PCB connector P363a pin labeled VREF must have +5vdc. Pin
labeled, as VOLP is variable DC needed by the micro to establish volume control
data.

This voltage usually disappears on the DSP PCB located behind front panel. Since
the DSP is a dual layer PCB type the voltage needed could disappear anywhere by
the interconnect pins existing between the front and back traces. Begin at P706a
edge connector labeled VOL REF.

**To access the PCB you may simply remove all the power amplifiers and set
them to the side until all audio is obtained at the pre-amp out stage. With the
amplifier assemblies removed there is a better chance of maneuvering a DVM or
OSCILLOSCOPE probe.

You can use the PRE-AMP output jacks to test audio and confirm all functions
before reassembling amplifier block in its place.