The Marantz 2230 is a classic stereo receiver from the 1970s known for its warm sound and distinctive blue dial lighting. This recap service manual provides detailed instructions for replacing electrolytic capacitors to restore optimal performance, improve sound quality, and extend the lifespan of this vintage audio equipment. Below are key sections covering safety precautions, required tools, capacitor replacement procedures, testing methods, and troubleshooting guidelines.
Before beginning any service work on the Marantz 2230, observe these critical safety measures to prevent injury and equipment damage.
| Precaution | Description |
|---|---|
| Power Disconnection | Always unplug the receiver from AC power before servicing |
| Capacitor Discharge | Discharge all large capacitors using appropriate resistors |
| Static Protection | Use anti-static wrist strap when handling circuit boards |
| High Voltage Areas | Identify and avoid contact with high voltage sections |
| Proper Grounding | Ensure proper grounding of all test equipment |
| Component Handling | Handle circuit boards carefully to avoid damage |
| Work Area | Use clean, well-lit workspace with adequate ventilation |
| Documentation | Keep service manual and schematics readily available |
Gather all necessary tools and replacement components before beginning the recap procedure.
WARNING! Use only high-quality audio-grade capacitors for replacement to maintain original sound characteristics.
Proper disassembly is crucial for safe and effective recapping.
CAUTION! Handle glass dial face carefully to prevent cracking or scratching.
After recapping, perform comprehensive testing and calibration.
Initial Testing: Use dim-bulb tester for first power-up. Check DC offset at speaker terminals. Verify proper bias current adjustment.
Calibration Steps: Adjust idle current to 10mA per service manual. Set DC offset to 0mV. Verify proper operation of protection circuit. Check all input sources (phono, aux, tuner). Test headphone output functionality. Verify tone control and balance functions.
Careful reassembly ensures proper operation and appearance.
Tip: Test all functions before final reassembly to avoid repeated disassembly.
Verify that the recapped receiver meets original specifications.
WARNING! Do not operate without proper load or heat sinking during testing.
Typical problems encountered during Marantz 2230 recapping and their resolutions.
Original performance specifications for reference and verification.
Recommended replacement components and suppliers.
| Component Type | Recommended Replacement | Supplier |
|---|---|---|
| Main Filter Caps | Nichicon KG Gold Tune | Parts Connexion |
| Coupling Caps | Elna Silmic II | Mouser Electronics |
| Small Electrolytics | Nichicon UKL | Digi-Key |
| Film Caps | WIMA MKS2 | Newark Electronics |
| Power Transistors | Original or NTE equivalents | B&D Enterprises |
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| No power after recap | Incorrect capacitor polarity | Check all capacitor orientations; verify power supply voltages |
| Hum or buzz | Grounding issues or filter caps | Verify ground connections; check main filter capacitors |
| One channel dead | Output transistor or driver issue | Check output transistors; verify driver stage components |
| Distorted sound | Bias misadjustment or bad caps | Readjust bias current; check coupling capacitors |
| Protection circuit engaged | DC offset or short circuit | Measure DC offset; check for shorts in output stage |
Professional Service: If problems persist, consult qualified vintage audio technician.
Support Resources: Marantz-specific forums and vintage audio repair communities