Verified and documented hard-to-find information about consumer products, including repair solutions, obsolete parts, replacement part numbers, compatibility, specifications, diagnostics, vintage electronics, appliances, arcade hardware, and other obscure technical knowledge.
Player: Sony CDP-C301M
Sony belt part number: 4-930-528-01
Timing belt: 83 teeth
Pitch: 2 mm
Pitch length: approximately 166 mm
Width: approximately 2 mm
Repair status: VERIFIED — REPLACEMENT INSTALLED AND WORKING
Evidence: Original belt physically measured, replacement identified, physically installed, and operationally tested
The timing belt used in the Sony CDP-C301M CD player has been physically identified, measured, replaced, and tested.
The confirmed working replacement is:
Sony part number: 4-930-528-01
The original timing belt was physically measured as:
A replacement Sony 4-930-528-01 belt was obtained, installed in the CDP-C301M, and tested.
The player operates correctly with the replacement belt installed.
Result: Sony 4-930-528-01 — PHYSICALLY INSTALLED — VERIFIED WORKING
The Sony CDP-C301M uses a toothed timing belt as part of its disc-changing mechanism.
When this belt deteriorates, stretches, breaks, or is missing, identifying a suitable replacement can be difficult because the required dimensions and tooth count are not obvious from the player itself.
Reliable replacement information for this specific mechanism is also difficult to locate.
The purpose of this repair was therefore not simply to find a belt that appeared similar, but to identify the original belt specifications and confirm a replacement through actual installation and operation.
The original Sony timing belt was physically examined and measured.
The following specifications were established:
| Specification | Verified measurement |
|---|---|
| Tooth count | 83 teeth |
| Tooth pitch | 2 mm |
| Pitch length | approximately 166 mm |
| Belt width | approximately 2 mm |
The pitch length is derived from the verified tooth count and pitch:
83 teeth × 2 mm pitch = approximately 166 mm pitch length
These measurements provide useful identification information when evaluating possible replacement belts.
The replacement belt obtained for the repair was:
Sony 4-930-528-01
This belt was physically installed in the Sony CDP-C301M and successfully operated the mechanism.
This moves the part number beyond an unverified cross-reference or dimensional estimate.
Sony 4-930-528-01 is a physically tested and confirmed working replacement in the documented CDP-C301M.
The original belt is a small synchronous / toothed timing belt.
Its verified tooth spacing is:
2 mm pitch
The combination of:
provides a useful dimensional reference for identifying the belt.
However, dimensional similarity alone should not be treated as proof that another belt is a correct replacement.
The successful repair documented here used the actual Sony 4-930-528-01 replacement.
The original belt measured approximately:
2 mm wide
This is unusually narrow compared with many commonly available industrial timing belts.
A wider belt with the correct tooth count and pitch should not automatically be assumed to fit the mechanism.
Pulley width, surrounding clearances, tracking, and other mechanical factors may prevent a wider belt from operating correctly.
For this reason, the approximately 2 mm original belt width is an important part of the replacement specification.
A Sony 4-930-528-01 replacement belt was obtained and installed in the CDP-C301M.
Following installation, the player was tested through normal operation.
The mechanism operated correctly with the replacement belt installed.
Overall repair result: SUCCESSFUL
Vintage audio replacement-part information is frequently copied between parts lists, seller listings, forum posts, and compatibility databases without confirmation that the suggested component has actually been installed.
That can be particularly problematic with timing belts because small differences in:
can determine whether a belt actually works.
For this repair, the original belt was physically examined and measured, and the identified Sony replacement was subsequently installed and tested.
The specifications on this page therefore represent a completed repair rather than an untested compatibility suggestion.
The measured dimensions may resemble commercially available synchronous timing belts.
However, a nominally similar industrial belt should not automatically be considered equivalent to Sony part 4-930-528-01.
In particular, belt width can be a problem because many industrial belts with otherwise similar specifications are substantially wider than the approximately 2 mm belt used in the CDP-C301M.
A candidate industrial belt should therefore be treated as unverified unless it has been physically installed and successfully operated in the player.
The confirmed repair documented here used Sony part:
4-930-528-01
The CDP-C301M mechanism also contains a separate flat rubber belt.
This is distinct from the 83-tooth timing belt documented on this page.
The flat belt was also replaced during work on the player, but the specifications documented here apply specifically to the toothed timing belt.
Do not use the 83-tooth timing-belt specifications when attempting to identify the separate flat belt.
This firsthand repair confirms the following for the Sony CDP-C301M:
This information is based on physical inspection, measurement, installation, and operational testing.
This entry documents one physically completed Sony CDP-C301M repair.
The dimensional measurements are intended primarily to document the original belt and assist with future identification.
They should not be interpreted to mean that every commercially available 83-tooth, 2 mm-pitch belt will fit the CDP-C301M.
Width, tooth profile, material, pulley engagement, and mechanism clearance may also affect compatibility.
Where available, the physically verified Sony 4-930-528-01 replacement remains the confirmed reference documented by this repair.
Sony CDP-C301M timing belt — Sony CDP-C301M belt replacement — Sony 4-930-528-01 — 4-930-528-01 timing belt — Sony CD player 83 tooth belt — 83 tooth 2 mm pitch timing belt — 166 mm timing belt — Sony CDP-C301M changer belt — CDP-C301M belt size — CDP-C301M repair — Sony CD changer timing belt
Player: Sony CDP-C301M
Component: Disc mechanism timing belt
Sony part number: 4-930-528-01
Original tooth count: 83 teeth
Original pitch: 2 mm
Calculated pitch length: approximately 166 mm
Original width: approximately 2 mm
Replacement physically installed: YES
Operationally tested: YES
Final result: VERIFIED WORKING
For the Sony CDP-C301M, the confirmed replacement timing belt is:
Sony 4-930-528-01
The original belt was physically measured at 83 teeth with a 2 mm pitch and approximately 2 mm width, corresponding to an approximately 166 mm pitch length.
Sony part 4-930-528-01 was subsequently installed in the player and tested successfully.
Repair status: VERIFIED — REPLACEMENT INSTALLED AND WORKING
Last updated: September 2026