Sharp XL-DK257N Service Manual page 73

(4) PLL system check.
When a disc is loaded, start play operation.
The RF waveform is normal, but the TOC data cannot be read.
Check the TMAX waveform. (Figure 6)
Check around Pins 72, 73, 74, 75, 76 and 78 on IC1.
(5) Others.
The RF waveform is normal and the time is displayed
normally, but no sound is produced. Or the sound has
dropouts.
Is pin 65, 66 and 67 on IC1. (Figure 7)
If OK, Check the unit.
9
67
LRCKI
IC1
BCKI
10
66
IC1
AIN
11 65
IC1
Figure 7
Yes
7
IC1
74
8
76
IC1
13
6
IC1
9
1
IC1
No There are too many error flags on a damaged disc which makes
error correction impossible.
Check again using a known good disc.
7 – 4
TMAX
LPFO
DMO
FOO
Figure 6
XL-DK257N