Onkyo TX-DS494 - Service Manual

Other manuals for Onkyo TX-DS494

Instruction Manual36 pages

Questions and Answers

K
Katherine BrownAug 14, 2025
What to do if my Onkyo TX-DS494 has power but no sound?
- A
  Angela JohnsonAug 14, 2025
  If your Onkyo Receiver powers on but produces no sound, the issue might stem from several causes. First, ensure the turntable stylus tip is clean. If the MUTING indicator is flashing, deactivate it by pressing the MUTING button on the remote controller. Check that the treble control isn't set too high. Also, verify all connections and speaker leads are properly connected. If “PROTECT” is displayed, the amplifier protection circuitry has been activated, and you should contact your Onkyo Service Center.
A
Anna Salas MDAug 18, 2025
How to fix hum or low-frequency noise on Onkyo TX-DS494?
- J
  Julia KingAug 18, 2025
  If you experience a hum or low-frequency noise with your Onkyo Receiver, it could be due to a poor or missing input ground. Inspect the outer conductor of the input plugs. Also, check for a poor or missing phono motor ground and ensure a proper ground connection. Additionally, adjust the placement of the audio connection cables on the rear panel to reduce hum.
K
Kevin JonesAug 21, 2025
Why is there no sound from subwoofer on my Onkyo TX-DS494 Receiver?
- A
  Anna SmithAug 21, 2025
  If you're not getting any sound or very little volume from the subwoofer connected to your Onkyo Receiver, the subwoofer mode may be set to “OFF”. Check the subwoofer mode setting to ensure it is properly configured.
T
Timothy VasquezAug 25, 2025
Why no sound from the center speaker on my Onkyo Receiver?
- A
  Allison BowmanAug 25, 2025
  If you're not getting any sound or very minimal sound from the center speaker of your Onkyo Receiver, first check the connection between the receiver and the speaker. If the listening mode is set to STEREO or ORCHESTRA, the center speaker outputs only the effect sound. If the speaker configuration is set to 2 ch or 4 ch, set it to 3 ch or 5 ch.
J
Jeffrey JenkinsAug 27, 2025
What to do if Onkyo TX-DS494 sound is rough or scratchy?
- J
  John SnowAug 28, 2025
  If you are experiencing rough or scratchy sound or the high range is not clear on your Onkyo Receiver, the stylus of the turntable pick-up may be worn and needs replacement, or the turntable stylus tip may be dirty and needs cleaning. Also, the treble control may be set too high, so turn it down.
A
Autumn ReillyAug 31, 2025
Why no picture on TV screen when using Onkyo TX-DS494 Receiver?
- S
  Shane LivingstonAug 31, 2025
  If no picture appears on your TV screen (or monitor) when connected to the Onkyo Receiver, ensure that the TV (or monitor) is set to receive the input from the receiver. Also, check that the video cable is securely connected.
S
smithstephenSep 3, 2025
What to do if desired picture does not appear on Onkyo TX-DS494?
- L
  Lisa JonesSep 3, 2025
  If the desired picture does not appear when using your Onkyo Receiver, ensure that the correct input source is selected.
R
Richard Evans DVMSep 7, 2025
Why AM stations cannot be received on Onkyo TX-DS494 Receiver?
- M
  Mason BakerSep 7, 2025
  If you can't receive AM stations on your Onkyo Receiver, make sure the AM loop antenna is attached to the AM antenna terminals.
M
Mark CarlsonSep 10, 2025
Why does my Onkyo TX-DS494 howl when the volume is high?
- L
  Lynn MortonSep 12, 2025
  If you are experiencing a howling sound when the volume is turned up on your Onkyo Receiver, the turntable and speakers may be too close together. Move them farther apart.

Summary

Safety Related Component Warning

Specifications Overview

Amplifier Section Specifications

Details on power output, distortion, input sensitivity, and impedance for the amplifier.

Service Procedures

Replacing Fuses

Instructions for replacing fuses, including part numbers and ratings for safety.

Unit Initialization Procedure

Post-Service Safety Check

Safety checks required after service, focusing on insulation resistance.

Exploded View - Main Part

Exploded View - Front Part

Exploded View Parts List - 1

Exploded View Parts List - 2

Exploded View Parts List - 3

Block Diagram Overview

Microprocessor Connection Diagram

Microprocessor Terminal Description

Schematic Diagram - 1

Schematic Diagram - 3

Schematic Diagram - 5

Printed Circuit Board Parts List - 1

Printed Circuit Board Parts List - 2

Printed Circuit Board Parts List - 3

Printed Circuit Board Parts List - 4

Printed Circuit Board Parts List - 5

Printed Circuit Board Parts List - 6

Idling Current Adjustment Procedures

Protection Circuit Confirmation

Speaker Relay Confirmation

Confirming the speaker relay's ON and OFF behavior after power switch operations.

DC Detection Circuit Confirmation

Current Detection Circuit Confirmation

Onkyo TX-DS494 Specifications

Amplifier Section

continuous average power output	55 watts per channel min. RMS at 8 ohms
continuous power output	75 watts × 5 at 6 ohms
maximum power output	100 watts × 5 at 6 ohms

Tuner Section