AUDIO SHAKES
Is AUDIO HEAD scratched ?
No
Is input level at pin 85 of IC1002 about 0.4Vp-p ?
Yes
In playback, is the voltage at pin 4 of CP1003 2.6V ?
Yes
Check AUDIO BLOCK.
TROUBLESHOOTING GUIDE
Yes
Replace AUDIO HEAD.
No
Replace CAPSTAN DD UNIT.
No
Check IC1002.