Pioneer VSX-918V Volume Control Potentiometer Cleaning

Introduction

If your Pioneer VSX-918V Series receiver has developed control problems, this guide offers a method to potentially fix them without replacing the entire board. It details how to disassemble the receiver and clean the potentiometer using contact cleaner as a cost-effective solution.

Guide Warnings

• Working with high voltage equipment carries risks. Proceed with caution and at your own risk.
• Use common sense throughout the repair process. If you are unsure about your abilities, seek professional assistance.
• This is a temporary fix. For professional repairs, it is recommended to replace the board if the problem persists or if the potentiometer is damaged.

Guide Notes

• There is no guarantee that this fix will work, and the repair's longevity is not guaranteed.
• While this cleaning may resolve issues for some units, heavily used or damaged units may not be fully repaired or may fail again. If the potentiometer is suspected to be damaged by a previous owner, replacing the board or components is advised.
• This method may not work 100% of the time. If the issue persists, the control board may be damaged and require replacement.

Tools and Parts

Tools:

• Flathead Screwdriver (Phillips bit may be needed for disassembly)
• Magnetic Project Mat (Optional, for organizing screws)

Parts:

• DeoxIT (Recommended contact cleaner)
• RadioShack Control Contact Cleaner (Note: Availability may be limited)

Disassembly and Cleaning Procedure

Step 1: Unplug the receiver

Safety First: To ensure no residual power remains, unplug the receiver and allow it to sit for 48-72 hours. Before starting, disconnect the unit from the wall and hold the power button for 60 seconds to drain any remaining power from the capacitors.

Step 2: Remove the bottom faceplate screws

Locate and remove any screws present on the bottom of the faceplate. Additionally, remove the two screws securing the faceplate to the receiver. Keep these screws sorted as they may differ in size.

Step 3: Remove the side panel screws

Remove the two screws from the left side of the receiver. These screws are typically the same length. On the right side, remove the single screw, keeping it separate as it might differ in length.

Step 4: Remove the back screws

Caution: Exercise extreme caution as you may be exposed to charged components. Remove the three screws located on the back of the receiver. Once these are removed, the top cover should detach.

Step 5: Remove the retention pin on the faceplate

If a clip in the faceplate is missing, it indicates previous servicing. While not essential, it helps keep the bezel secure. This pin is factory-installed. To remove it, push it out from the back until it loosens, then remove it.

Step 6: Remove the faceplate screws

After removing the retention pin, unscrew the two screws holding the faceplate to the chassis. These screws are usually of the same length.

Step 7: Remove the knob from the receiver

Gently pull the control knob off the receiver. Apply firm, steady pressure. Excessive force could damage the knob or potentiometer.

Step 8: Disconnect the front panel flex cables

For iPod Direct models: Disconnect the wire connecting to the board. This board may need to be removed later. Disconnect the flat flex cable that links the front panel display to the rest of the receiver.

Step 9: Unclip the faceplate

Important: Any zipties cut during this process must be replaced upon reassembly to avoid protection mode errors. Cut the zipties securing the front panel wires to the fan to improve access. With the faceplate loose and cables disconnected, carefully unclip the faceplate from one side at a time. Lay it flat, ensuring enough space to access the front panel boards.

Step 10: Remove the iPod Direct board

Note: This procedure varies for non-iPod Direct receivers.

• iPod Direct models: Remove the four marked screws, then remove the support bracket and the PCB.
• Non-iPod Direct models: Remove the green and red screws. No other screws need removal.

Step 11: Remove the faulty control board

Identify and remove the three screws holding the volume control board to the receiver's front faceplate. One screw is unique and should be sorted separately.

Step 12: Spray contact cleaner into the potentiometer

Caution: Use contact cleaner sparingly. Over-application (more than 1-2 sprays) may render the board irreparable. With the control board accessible, spray a small amount of contact cleaner directly into the potentiometer. Clean any excess cleaner afterward.

Step 13: Wipe away any excess contact cleaner

Note: This fix may be temporary. If the problem returns, consider replacing the board or potentiometer. Allow the switch to dry for at least 1 hour before reassembly. If zipties are unavailable, tuck wires away from the fan for a temporary solution.

Wipe off any excess contact cleaner from the circuit board. Reinstall the control board once it is completely dry.

To reassemble your device, follow these steps in reverse order.