XL-UH220H (serv.man4) - Sharp Audio Service Manual (repair manual). Page 8

XL-UH220H

2 – 1

• Adjustment

Since this CD system incorporates the following
automatic adjustment functions, readjustment is not
needed when replacing the pickup. Therefore, dif-
ferent PWBs and pickups can be combined freely.

Each time a disc is changed, these adjustments are
performed automatically. Therefore, playback of
each disc can be performed under optimum condi-
tions.

1) Offset adjustment (The offset voltage between the

head amplifier output and the VREF reference volt-
age is compensated inside the IC.)

* Focus offset adjustment

* Tracking offset adjustment

2) Tracking balance adjustment

3) Gain adjustment (The gain is compensated inside

the IC so that the loop gain at the gain crossover
frequency will be 0 dB.)

* Focus gain adjustment

* Tracking gain adjustment

* 'CHECKING'

If Error is detected, 'CHECKING' will be displayed
instead of 'ER-CD**'. 'ER-CD**' display will only be
displayed when error had been detected for the 5

th

times.

10*

CAM error. Can't detect CAM switch when CAM is moving. 

11*

When it detect cam operation error during initialize process.

20*

TRAY error. Can't detect TRAY switch when TRAY is mov-
ing.

21*

When it detect TRAY operation error during initialize pro-
cess.