Brand: SONY
Category: Audio
Document Type: Manual
Language: EN
Available Languages: EN , ES
Manual for D-121
Uploaded: Nov. 21, 2025, 8:42 p.m.
Warranty Information
No warranty information is provided in this manual.
Power Sources
The unit can be powered by two AA alkaline batteries (approx. 8 hours of playback) or the supplied AC power adaptor (DC IN 4.5 V jack).
Disc Playing
Insert disc with label side up, close lid, connect headphones, and press ►II to play. Use VOL control for volume. Various playing modes (Normal, INTRO, One Selection, Shuffle, RMS/Program) are available via the PLAY MODE button. REPEAT/ENTER can be used for repeat play. Press STOP (■) to stop playback.
Other Operations
Press ►II to pause and resume. Use AMS buttons (◄/►►) to locate selections. Search function (keep depressed ◄/►►) allows fast forward/backward playback. Remove disc by pressing pivot gently while lifting.
Audio Features
BASS BOOST switch enhances bass. AVLS selector limits volume to prevent hearing damage or high-level input distortion.
Connections
Can connect to amplifiers or cassette decks via LINE OUT jack using supplied connecting cord. Can record from other equipment via LINE IN or MIC jacks.
Troubleshooting and error codes
| Symptom | Cause and/or solution |
|---|---|
| Disc play does not start. | • Insert disc correctly with label surface up. • Dusty or defective disc. • Dirty or dusty lens. • Disc compartment lid not closed. • Moisture condensation (leave unit in warm place to evaporate). • AC power adaptor not plugged into wall outlet. • Mount plate not firmly connected. • Disc not placed on level surface. • HOLD switch is set. • If 12cm CD replaced with disc with few selections, may take >10 sec for play to start. |
| No sound from the headphones | • Weak alkaline batteries. • Headphones plug not firmly connected to PHONES jack. • Adjust VOL control. • Dirty plug. |
| No sound from the connected speakers | • Check connections. • Amplifier not turned on. |
| Skipping of sound | • Dirty or defective disc. • Dirty lens. • Strong vibration. |
| Disc play does not stop when you turn off the engine of the car. | • Press to stop operation. |
| The "no disc" indication appears in the display window. | • Place the CD with label surface up. • Replace CD if badly damaged. |
| The "Hi dc in" indication appears in the display window. | • Use the supplied AC power adaptor. |
| When using with batteries, the battery life is short. | • Manganese batteries are used. Use alkaline batteries. |