BE/Body Electrical System — Sound jumps, page 113

C     Sound jumps

Check that player is correct installed. → No → Player installation faulty.
↓ Yes
Does sound jump only when is jolt? → Yes → Does sound jump every time there is jolt? → Yes → Player faulty.
↓ No                                         ↓ No
                                            Normal

Does sound jump always at same place on same song? → Yes → CD faulty.
↓ No
Is CD damaged or dirty? → Yes → CD faulty
↓ No
Has player been exposed to large temperature change? → No → Player faulty.
↓ Yes
Operate air conditioner for about 30 minutes.
↓
Does sound still jump? → Yes → Player faulty.
↓ No
Normal (Dew formation because of temperature change.)