Page 2
COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE WITH MARK 0 ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.
STR-DB798 SECTION 1 SERVICING NOTES • MODEL IDENTIFICATION UNLEADED SOLDER Boards requiring use of unleaded solder are printed with the lead- – Back Panel – free mark (LF) indicating the solder contains no lead. (Caution: Some printed circuit boards may not come printed with...
Page 5
STR-DB798 SERVICE POSITION When checking without back panel, it is necessary to connect the clip for GND to a chassis. COMP-V board (JW300) DIGITAL board (EB1101) clip AU-IN board (JW101) clip -MAIN BOARD SERVICE POSITION- DIGITAL board rear panel COMP-V board...
STR-DB798 SECTION 2 This section is extracted from instruction manual. GENERAL Receiver PUSH wf ALPHABETICAL ORDER M - Z SPEAKERS (OFF/A/B/A+B) wh MAIN MENU 4 SURR BACK DECODING ql A - L MASTER VOLUME –/+ qa TUNING –/+ w; A.F.D. qj...
STR-DB798 SECTION 3 DISASSEMBLY • This set can be disassembled in the order shown below. 3-1. DISASSEMBLY FLOW 3-2. CASE (Page 7) 3-3. COMP-V BOARD (Page 8) 3-4. BACK PANEL BLOCK (Page 8) 3-5. DIGITAL BOARD, A/V SYNC BOARD (Page 9) 3-6.
STR-DB798 3-7. MAIN BOARD BLOCK 1 connector (CN418) 3 four screws (BVTP3 × 8) 2 four screws (BVTP3 × 8) 1 three connectors (CN907, 909, 910) 4 MAIN board block 3-8. MAIN BOARD 2 three connectors (CN18, 28, 38) 6 A CLASS board...
STR-DB798 SECTION 4 TEST MODE TUNER FACTORY PRESET MODE VERSION CHECK MODE All preset contents are reset to the default setting. The version of the micro computer displayed. Procedure: Procedure: 1. While pressing the [MUSIC] and [PRESET TUNING --] buttons, 1.
STR-DB798 6-3. BLOCK DIAGRAM – AUDIO CONTROL Section – AUDIO SELECTOR IC101 J101 FRONT 5.1FL AUDIO SELECTOR IC173 12 5.1SL SURR VRIN LINE AMP AUDIO FLOUT BUFFER IC110 TRIM MULTI CH IN IC402 CENTER 28 5.1 C BUFFER (Page 16)
STR-DB798 6-6. BLOCK DIAGRAM – POWER SUPPLY Section – (AEP, Taiwan) S901 IMPEDANCE SELECTOR 8Ω T901 MAIN POWER TRANSFORMER 4Ω MUTING +5V REGULATOR B– Q824 BIAS LIMITER SWITCH RECT TUNER +9V B– Q2602 D914 +3.3V BIAS LIMITER SWITCH TUNER +3.3V...
Page 19
STR-DB798 • Note for Printed Wiring Boards and Schematic Diagrams • Circuit Boards Location Note on Printed Wiring Board: Note on Schematic Diagram: • X : parts extracted from the component side. • All capacitors are in µF unless otherwise noted. (p: pF) •...
STR-DB798 • See page 52 for Waveforms. • See page 53 for IC Block Diagrams. • See page 61 for IC Pin Function Description. 6-9. SCHEMATIC DIAGRAM – DIGITAL BOARD (1/4) – (1/4) IC1104 TORX147L R1127 OPTICAL R1120 DVD IN...
STR-DB798 • See page 52 for Waveforms. • See page 53 for IC Block Diagrams. • See page 61 for IC Pin Function Description. 6-10. SCHEMATIC DIAGRAM – DIGITAL BOARD (2/4) – (2/4) FB1201 JR1121 FB1202 (Page 22) C1213 C1214...
STR-DB798 • See page 19 for Circuit Boards Location. 6-15. PRINTED WIRING BOARDS – VIDEO Section – : Uses unleaded solder. J302 MONITOR OUT VIDEO BOARD VIDEO-AU BOARD (CHASSIS) VIDEO 1 IN HP-V3 VIDEO 1 AUDIO IN BOARD CN1091 (Page 30)
STR-DB798 • See page 19 for Circuit Boards Location. 6-27. PRINTED WIRING BOARD – A CLASS BOARD – : Uses unleaded solder. (Page 36) (Page 36) (Page 36) (Page 36) (Page 36) MAIN BOARD MAIN BOARD MAIN BOARD MAIN BOARD...
STR-DB798 • See page 19 for Circuit Boards Location. 6-28. PRINTED WIRING BOARDS – STAY Section – : Uses unleaded solder. (Page 40) (Page 40) (Page 40) (Page 36) A CLASS BOARD A CLASS BOARD A CLASS BOARD MAIN BOARD...
STR-DB798 • See page 19 for Circuit Boards Location. 6-35. PRINTED WIRING BOARDS – DC Section – : Uses unleaded solder. (Page 50) (Page 36) AC BOARD MAIN BOARD DC PWR BOARD CN51 CN422 (CHASSIS) CN912 MAIN POWER R912 TRANSFORMER...
Page 61
STR-DB798 • IC Pin Function Description DIGITAL BOARD IC1101 LC89056W-E (DIGITAL AUDIO INTERFACE RECEIVER) Pin No. Pin Name Description DISEL Selection signal input terminal of data input terminal Fixed at "L" in this set DOUT Digital data output to the digital optical transceiver...
Page 62
STR-DB798 DIGITAL BOARD IC1201 CXD9718BQ (AUDIO DIGITAL SIGNAL PROCESSOR) Pin No. Pin Name Description Ground terminal XRST System reset signal input from the system controller "L": reset EXTIN Master clock signal input terminal Not used Sampling frequency selection signal input terminal Not used VDDI Power supply terminal (+2.5V)
Page 63
STR-DB798 Pin No. Pin Name Description Ground terminal WMD0 External memory wait mode setting terminal Fixed at "H" in this set PAGE2 External memory page selection signal output terminal Not used Ground terminal 52, 53 PAGE1, PAGE0 External memory page selection signal output terminal Not used...
Page 64
STR-DB798 DIGITAL BOARD IC1703 MB91154PFV-G-125E1 (SYSTEM CONTROLLER) Pin No. Pin Name Description PW RY Relay drive signal output terminal (for main power) "H": relay on H/P RY Relay drive signal output terminal (for headphone) "H": relay on SP.A.RY Relay drive signal output terminal (for front A speaker) "H": relay on SP B RY Relay drive signal output terminal (for front B speaker) "H": relay on...
Page 65
STR-DB798 Pin No. Pin Name Description Ground terminal Not used DAB_SEL DAB selection signal output terminal Not used RDS.DATA RDS serial data input from the tuner unit (AEP and UK models only) TUNER ST FM stereo detection signal input from the tuner unit...
Page 66
STR-DB798 Pin No. Pin Name Description DA1LAT Serial data latch pulse signal output to the D/A converter DACCLK Serial data transfer clock signal output to the D/A converter DAC_MDI Serial data output to the D/A converter NO_USE Not used Power supply terminal (+3.3V)
Page 67
STR-DB798 A/V SYNC BOARD IC2010 CXD9722TQ (LIP SYNC ADJUST) Pin No. Pin Name Description 1 to 5 D1 to D5 Two-way data bus with the SD-RAM Power supply terminal (+3.3V) 7, 8 D6, D7 Two-way data bus with the SD-RAM...
Page 68
STR-DB798 Pin No. Pin Name Description Ground terminal DLDRI Surround back audio data input from the audio digital signal processor CSWI Center and sub woofer audio data input from the audio digital signal processor SLSRI Surround audio data input from the audio digital signal processor...
STR-DB798 SECTION 7 EXPLODED VIEWS NOTE: • Items marked “*” are not stocked since they • -XX and -X mean standardized parts, so they The components identified by mark 0 or dotted line with mark 0 are may have some difference from the original are seldom required for routine service.
STR-DB798 SECTION 8 4-8 OHM A CLASS ELECTRICAL PARTS LIST NOTE: • Due to standardization, replacements in the • Items marked “*” are not stocked since they The components identified by mark 0 or dotted line with mark 0 are parts list may be different from the parts are seldom required for routine service.
Page 77
STR-DB798 A CLASS Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark C2711 1-137-503-11 FILM 100PF 100V Q2602 8-729-024-93 TRANSISTOR 2SB1565E C2807 1-137-389-11 MYLAR 0.0022uF 5% 100V Q2603 8-729-140-84 TRANSISTOR 2SC1841-PAFAEA C2808 1-137-389-11 MYLAR 0.0022uF 5% 100V...
Page 85
STR-DB798 DIGITAL Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark R1023 1-216-809-11 METAL CHIP 1/10W IC1204 8-759-546-74 IC TC7WH157FU (TE12R) R1024 1-216-809-11 METAL CHIP 1/10W IC1401 8-759-560-56 IC PCM1800E/2K R1025 1-216-809-11 METAL CHIP 1/10W IC1402 8-759-636-55 IC M5218AFP...
Page 86
STR-DB798 DIGITAL Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark R1226 1-216-864-11 SHORT CHIP R1583 1-216-821-11 METAL CHIP 1/10W R1304 1-216-841-11 METAL CHIP 1/10W R1584 1-216-845-11 METAL CHIP 100K 1/10W R1590 1-216-832-11 METAL CHIP 8.2K 1/10W...
Page 87
STR-DB798 DIGITAL DIRECT DISPLAY Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark R1652 1-216-833-11 METAL CHIP 1/10W R1715 1-216-833-11 METAL CHIP 1/10W R1653 1-216-833-11 METAL CHIP 1/10W R1716 1-216-833-11 METAL CHIP 1/10W R1654 1-216-833-11 METAL CHIP...
STR-DB798 REVISION HISTORY Clicking the version allows you to jump to the revised page. Also, clicking the version at the upper right on the revised page allows you to jump to the next revised page. Ver. Date Description of Revision...