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7 Tracking Error Offset Adjustment 2
-Purpose :
To check the offset of the tracking pre-amp is zero
and adjust if necessary.
'Symptoms of Mal-adjustment :
Track search NG, Carriage runaway, Poor playability.
*Measuring
-DC V Meter
Equipment / Jig
'Measuring Point
-TEY
Test Disc , Mode
*No disc, TEST MODE
-Adjustment Point
*VR1001(TE OFFSET VR)
MAIN UNIT
OC V Meter
Adjustment Procedure
1.Switch the regulator on.
2.Using VR1001, adjust TEY to 0 + 25mV w.r.t. REFO.
8 Tracking Balance Adjustment 2
-Purpose :
SET volume was
re-adjusted in the previous step.
-Symptoms of Mal-adjustment:
Track search NG,Poor playability, carriage runaway.
-Measuring
Equipment / Jig
*Measuring Point
'TEY
-VR1002 (T.BAL VR)
Oscilloscope, L.P.F.
-Adjustment Point
MAIN UNIT
Pull up the TOF terminal to the V+5 terminal with a 56kQ resistor.
(This is in order to cancel lens offset in the tracking direction.)
{Sub-number of the main unit's p.c.board is -C and after.)
NOTE: If the sub-number of the main unit's p.c.board is -B, it means
there is no TOF terminal, so instead of attaching a pull-up resistor,
adjust the item by tilting 45° in the direction where the grille is |ift-
ed.
Adjustment Procedure
1.Load disc and switch the regulator on.
2.Position the PU unit in the center of the disc using
the FF & REV keys.
3.Close focus by pressing key 9.
4.Observing the TEY waveform on the oscilloscope,
adjust VR1002 until the positive and negative halves
have the same amplitude (See waveform 7-9).
Check
After adjustment the TEY waveform should have an
amplitude of 1.5+0.65 Vpp (ABEX TCD-784 or SONY
TYPE 4)
5. Remove the pull-up resistor after completingad-
justment.
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