Sharp CD-XP7700 Service Manual - Page 15

TUNER SECTION fL: Low-range frequency fH: High-range frequency • AM IF/RF Signal generator: 400 Hz, 30%, AM modulated Test Stage Frequency Frequency Setting/ Instrument Display Adjusting Connection Parts AM IF 450 kHz 1,702 kHz T351 *1 AM Band - Coverage 530 kHz (fL): T306 *2 1.1 ± 0.1 V AM Tracking 990 kHz 990 kHz (fL): T303 *1 *1. Input: Antenna *2. Input: Antenna Output: TP302 Output: TP301 • FM RF Signal generator: 1 kHz, 40 kHz dev., FM modulated Test Stage Frequency Frequency Display Setting/ Instrument Adjusting Connection Point FM Band - Coverage 87.50 MHz T301 (fL): *1 1.3 V ± 0.1 V FM RF 98.00 MHz 98.00 MHz L312 *2 (10-30 dB) *1. Input: Antenna Output: TP301 *2. Input: Antenna Output: Speaker terminal • FM IF Signal generator: 10.7 MHz, FM modulated Test Stage Frequency Frequency Display Setting/ Instrument Adjusting Connection Point IF 10.7 MHz 98 MHz T302 *1 (Turn the core of trans- former T302 fully counter- clock wise) *1. Input: Antenna Output: TP301 MAIN PWB CD-XP700/CD-XP7700 CD SECTION • Adjustment Since this CD system incorporates the following automatic adjustment functions, readjustment is not needed when replacing the pickup. Therefore, different 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 conditions. Items adjusted automatically (1) Offset adjustment (The offset voltage between the head amplifier output and the VREF reference voltage is compensated inside the IC.) * Focus offset adjustment * Tracking offset adjustment (2) Tracking balance adjustment (waveform drawing Fig.15-2 EFBL) (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 CD ERROR CODE DESCRIPTION Error Explanation 01 When Pickup set inner position, inner switch cannot detect 'ON' level for 10 secs. When tray moves to Open/Close, Open/Close switch cannot detect 'ON' level for 7 secs. 10* When disc table rotate to target position. Clamp switch cannot detect 'ON' level for 7 secs. When disc table set to Disc1 position for 1 st time, 11* "CLAMP SW", "DISC NO SW" and "OPEN/CLOSE" cannot detect 'ON' level for 14 secs. When it changes to CD function, DSP cannot read 31 initial data. * 'CHECKING' If Error is detected, 'CHECKING' will be display instead of 'ERCD**' display. 'ER-CD**' display will only be display when error had been detected for the 5 th times. Stopped T CH1=500 mV DC 10:1 CH2=200 mV DC 10:1 CH3=1 V DC 10:1 1999/04/05 20:26:47 500 ms/div (500 ms/div) NORM:20 kS/s CNP301 AM/FM LOOP ANTENNA IC301 FM BAND COVERAGE fL T301 T351 1 T303 T302 FM IF FM RF L312 R316 TP301 T306 AM IF AM TRACKING fL AM BAND COVERAGE fL R356 TP302 Figure 15-1 ADJUSTMENT POINTS T FDO 1 TE 3 EFBL 2 =Filter= Smoothing : ON BW : FULL =Offset= CH1 : 0.000 V CH2 : 0.000 V CH3 : 0.00 V CH4 : 0.00 V =Record Length= Main : 100K Zoom : 2k Figure 15-2 CH2 v/DIV 200 mV =Trigger= Mode : SINGLE Type : EDGE CH1 Delay : 0.0 ns Hold off : 0.2 µs - 15 -