Philips CDR775 - Faultfinding Trees (Continued); CD Module Faultfinding

Faultfinding trees
GB 47CDR775 7.
7.2 CD Module
Figure 7-5
NO DISC
POWER ON
PRESS
<OPEN/CLOSE>
LOAD DISC
(CD-DA OR PARTIALLY
RECORDED CD-R/CD-RW)
PRESS <OPEN/CLOSE>
DISC
DETECTION
STARTS?
DISPLAY?
• CHECK FLEX CONNECTION FROM CDR MAIN BOARD
• POWER SUPPLY
⇒ +5V, +12V AT TESTPOINTS 28 AND 27
⇒ +5V AT IC7005 PIN 14
⇒ +3V3 AT IC7000 PINS 5,17,21,57, CHECK SAFETY RESISTORS
⇒ +5V AT IC7020 PIN 25
⇒ +10V AT IC7020 PINS 26, 27, 28
⇒ +12V AT IC7021 PIN 5, CHECK SAFETY RESISTOR R3131
⇒ +12V AT IC7022 PIN 5, CHECK SAFETY RESISTOR R3154
⇒ +5V AT IC7025 PIN 16
⇒ +5V AT IC7202 PIN 38, CHECK SAFETY RESISTOR R3308
⇒ +3V3 AT IC7309 PINS 4 AND 13, CHECK SAFETY RESISTORS R3215, R3216
• CLOCKS
⇒ 8.4672MHz AT TESTPOINT 7
⇒ 12MHz AT TESTPOINTS 29 AND 30
⇒ 11.2896 AT TESTPOINT 10
• DISPLAY
⇒ SEE FAULTFINDING GUIDE DISPLAY BOARD
• MICROPROCESSOR 7202
DIAGNOSTIC SOFTWARE : MECHANICAL SERVICE DIAGNOSTICS CD LOADER : TRAY TEST
⇒ CHECK TRAY MOTOR VOLTAGES
TRAY+, TRAY-
⇒ MICROPROCESSOR 7202
⇒ CHECK TRAY MOTOR DRIVER IC7021
⇒ REPLACE OR REPAIR CD LOADER ASSY:
TRAY MOTOR ASSY 02, BELT 11
TRAY?
NO
NO
NO
YES
YES
YES
TOC?
YES
NO
DIAGNOSTIC SOFTWARE : MECHANICAL SERVICE DIAGNOSTICS CD LOADER :
FOCUS TEST & SLEDGE TEST
⇒ CHECK WIRING TO CDM
⇒ CHECK POWER DRIVERS 7021, 7022, 7020
⇒ CHECK VOLTAGES ON POWER DRIVERS (SEE CIRCUIT DIAGRAMS)
⇒ TESTPOINTS 4, 5, 6 : PULSE DENSITY MODULATED SIGNALS
• HF PATH
⇒ TESTPOINTS 1, 2, 3, 9 : EYEPATTERN
⇒
CHECK
RW AT TESTPOINT 8 : HIGH FOR CDDA AND CDR DISC, LOW FOR
CDRW DISC. EYEPATTERN OF CDRW DISC WILL BE AMPLIFIED (
≈
X 2.5).
EYEPATTERN OF CDDA DISC WILL BE ATTENUATED(
≈ X 0.8)
⇒
CHECK
S1,S2
AT TESTPOINTS 25 AND 26 (SEE CIRCUIT DIAGRAMS)
⇒ TESTPOINTS 20, 21, 22: I
2
S
DATA, WCLK, SCLK
• REPLACE OR REPAIR CD LOADER ASSY (CDM MECHANISM)
SEE NEXT PAGE:
PLAYBACK
CD MODULE
⇒ +5V AT CONN. 1000 PINS 1 AND 3
⇒ +12V AT IC7120 PIN 8, CHECK SAFETY RESISTOR R3263
⇒ 2.1168MHz AT TESPOINT 20
⇒ 44.1kHz AT TESTPOINT 21
•
CL 96532086_030.eps
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