Philips-DVDR-985-Service-Manual-2 电路图 维修手册.pdf

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1、Philips DVDR985 Technical Training Manual Philips Service and Quality/Training One Philips Drive Knoxville, TN 37914-1810 P. O. Box 14810 PH: 865-521-4397 FAX: 865-521-4818 EMAIL: TECHNICAL.TRAININGPHILIPS.COM RadioFans.CN 收音机爱 好者资料库 Introduction This Manual is intended for use by the Service Techni

2、cian. The first portion of this manual con- tains a basic description of disc based data play- back and recording technologies. Self Diagnostics are included to aid in troubleshoot- ing. Technical Descriptions of the circuitry is fol- lowed by a Troubleshooting Section. The DVDR985 is the forth in a

3、 line of DVD recorders. The DVDR1500 was the first. Recordings can be made from broadcast trans- missions, and from other analog or digital sources. The DVDRW format allows the user to record and erase a disc many times. The record- ed discs will play on most existing and future DVD players. The DVD

4、R985 has a connection for DV or Digital camcorders via an I-Link or Firewire connection. This connection technically is called an IEEE 1394 connection. This machine records on 4.7Gbyte DVD+R and DVD+RW discs. This machine uses a real-time MPEG2 Variable Bit Rate, VBR, Video encoder. The DVDR985 play

5、s back DVD Video, Video CD, Audio CD, CD-R, and CD-RW discs. Its many features include: Favorite Scene Selection for easy editing, Index Picture Screen for instant overview of contents, Digital Time Base Correcter, Digital Audio output (DTS, AC- 3, MPEG, PCM), TruSurround for 3D sound, Zoom + Perfec

6、t Still. It is Widescreen, 16:9 compatible, and has a Universal Remote Control, 20 disc resume, Disc Lock, and One Touch Recording. Virgin Mode The DVDR985, when first hooked up, needs to get information from the user about what lan- guage and what local broadcast system the unit is going to operate

7、 with. Use the remote to make those selections. The unit will not operate until this process is completed. If you want the recorder to start up in Virgin mode, unplug the recorder. Plug the recorder in again while hold- ing the STANDBY-ON button. DVD Basics Philips with nine other manufacturers chos

8、e a format specification for DVDR and RW on March 16, 2001. This new format uses Real Time recording. Its recording is compatible with DVD- Video, and DVD ROM. The data blocks use loss- less linking. The physical layout matches very closely that of DVD ROM. See Figure 1. It also uses Direct Overwrit

9、e when a RW disc is used. Laser Technology CDs use a red laser created by a diode and lens system often called a Light Pen. Refer to Figure 2. The narrow beam of light is focused onto the reflective layer of a disc. At the instant that focus is achieved, the disc is spun. The laser starts on the inn

10、ermost tracks of the CD and reads out- ward. At the beginning of the disc is the Table of Contents. At the bottom of the Light Pen are Monitoring Diodes. The Monitoring Diodes pro- vide information about focus and tracking. Data is retrieved from the disc in the form of pulses of Figure 1 DVD ROM Di

11、sc 1 RadioFans.CN 收音机爱 好者资料库 light reflecting from the disc. The pulses are created by Pits in the Reflective Layer of the disc. The Pits reflect less light than the intact surface of the Reflective Layer, called Lands. Disc Mechanical Layout The DVD and CD share much of their tech- nology. We will

12、start with CDs and work our way to the DVD. The CD is a plastic disc 120mm in diameter, with a thickness of 1.2mm. Refer to Figure 3. It has a silver col- ored Reflective Layer. The maximum playing time for a music recording on a Compact Disc, CD, is 74 Min. The CD is less vulnerable to damage than

13、an analog record. That does not mean it does not have to be treated with care. Dirt and heavy scratches can interfere with playability. Figure 2 CD Laser Operation Figure 3 Mechanical Layout of a CD. 2 RadioFans.CN 收音机爱 好者资料库 As shown in Figure 4, the CD is subdivided into three parts: the Lead In T

14、rack, the Program Area, and the Lead Out Area. These three sec- tions together are considered the Information Area. There is a hole in the center for holding the disc. The disc is held between two equally sized concentric rings. The rings have an inner diameter of 29mm and an outer diameter of 31mm.

15、 The Data on the disc is recorded on a spiral shaped track with pits and lands. The reflective side of the disc contains the tracks. The production of a disc is a high tech process explained in Figure 5. The process starts with glass that is photo etched. The glass is silver plated and is used as a

16、form for a metal cast. The metal cast is used to stamp a nickel Mother Stencil. The Mother Stencil is used to stamp the Son Stencil. Son Stencils are used to stamp the foil of the discs. Aprotective layer and label are added. Read Process The Servo circuit is responsible for focusing the laser and m

17、oving the Light Pen to follow the spi- raling tracks on the rotating disc. The digital High Figure 4 - The Disc Figure 5 - Creating a CD 3 Frequency information, HF, is demodulated and stored in RAM. When the RAM is half full, the data is fed out to the Digital to Analog Converters. The speed of the

18、 rotating disc is servo controlled to keep the RAM half full. The analog signals are amplified and sent to the out- put connectors. Record Once Technology Disc Mechanical Layout From an external point of view, a DVD is the same as the CD. Recordable media creates the need for three physical layouts.

19、 There are three possible states of a disc: a blank disc, a partially recorded disc, and a full or finalized disc. The difference is in the way the Information Area is divided. The Information Area of a blank disc extends from 22.35 mm centered on the disc to 59 mm centered on the disc. Refer to Fig

20、ure 6. Apartially recorded discs Information Area has four sections: a PCA/RMAarea, a Lead In Area, a Recorded Program Area, and a Recordable Program Area. See Figure 6 for the dimensions. The PCAArea is the Power Calibration Area, PCA. The RMAArea is the Recording Management Area. Afully recorded o

21、r finalized discs Information Area has three sections: Alead in Area, the Program Area, and the Lead Out Area. See Figure 7 for the dimensions. The discs recordable layer contains major differ- ences from that of a stamped disc. The blank disc has a Pre-groove stamped into the record- able layer of

22、the disc. This is polycarbonant for DVD+Rs and organic dye material for DVD+RWs. This spiral Pre-groove is for the Servo circuit to provide a mechanical reference Figure 6 APartially Recorded Disc. Figure 7 Fully Recorded or Finalized Disc 4 during recording. The dye based RW recordable layer provid

23、es a reflectivity of 40% light return and 70% light return. 40 percent reflectivity rep- resents Pits and the 70% represent the Lands. Record Process The record process shares most of its mechani- cal operation with that of the play process. The main difference is how the Servo is locked to the disc

24、. The Servo follows the Pre-groove for Radial Tracking and disc speed. The speed of the disc is locked to a wobble signal that is part of the spiral grove stamped into the disc. The intensity of the laser beam is modulated from playback intensity to write intensity. As the disc reads the Pre-groove,

25、 the laser arrives at a position where a Pit is to be formed. The laser power increases from 4mW to 11mW. This raises the temperature of the disc to 250 degrees Celsius. The recordable layer melts, reducing its volume. The polycarbonate flows into the space vacated by the dye. The modulation from re

26、ad laser power to write laser power forms a pit and land pattern effectively the same as a prerecord- ed disc. Re-recordable Technology Disc Mechanical Layout Disc usage mechanically is identical to the recordable media. The only difference is the chemical make up of the recordable layer. The record

27、able layer is made up of an alloy of silver, indium, antimony and tellurium. Re-Recording Process The Re-Record process shares much of its oper- ation with that of a CDR. The blank discs Information Area is in a polycrystalline state. During recording, the laser power is modulated from 8mW to 14mW.

28、8mW is the playback laser power and 14mW is the record laser power. The polycrystalline state of the recordable surface changes, or melts at 500-700 degrees C into an amorphous state. The melted, amorphous areas reflect light less than the crystalline areas, creat- ing a pattern similar to the stamp

29、ed CD. Amajor difference of CDRWs from CDRs is the ability to erase. The Erase Process To Erase a CDRW disc, the recordable layer must be returned to its polycrystalline state. This is done by heating up the temperature of the recorded surface to 200 degrees C. This is less than the melting point. T

30、his is done at X2 record- ing speed. The slower speed allows time for the alloy to return to its proper state. This takes approximately 37 min. Some software erases the just the TOC on the disc and allows the disc to be rewritten. This method is not as reliable Over Writing Process Overwriting combi

31、nes the processes of erasing and writing. When the disc and Light Pen are in position to start writing the new data, the laser power starts modulating in the same manner as it does for normal recording with one difference. During the time there is to be a land, the laser power goes to the erase leve

32、l rather than the playback level. Figure 8 Mechanical Layout of a DVD 5 DVDs All of the previously discussed technologies apply to the DVD. Like CDs, DVDs are also stamped into play only discs. In this discussion, we will point out the differences between DVDs and CDs. If you are new to disc based t

33、echnolo- gy, you will want to start with the information pre- ceding this discussion. DVD Disc Mechanical Differences Most DVDs are single sided, however, the DVD specification allows for two readable layers, and the disc can be double sided. We will start our discussion with single sided, single la

34、yered discs. ADigital Versatile Disc, DVD, looks very similar to a CD. Refer to Figure 8. The Clamping Area is larger, starting at 11 mm centered to 16.5 mm centered. The Lead In Area is smaller, measuring 22.7 mm centered to 24 mm cen- tered. The Information Area is limited to 116mm centered. Two o

35、f the big differences between DVDs and CDs are the Pit and Land sizes, and the track widths. Refer to Figure 9. The Manufacturing process of a DVD is compa- rable to that of a CD. The main difference is the thickness. The DVD can be a double sided prod- uct. Each side is .6mm. The two sides are glue

36、d back to back, producing 1.2mm total thickness. Figure 8 - DVD Mechanical Layout Figure 9 DVD and CD Pit Structure. CDDVD 6 Wobble APre-groove is stamped on writable discs. All recordable DVD media types feature a micro- scopic wobble groove embedded in the plastic substrate. This wobble provides t

37、he recorder with the timing information needed to place the data accurately on the disc. During recording, the drives laser follows this groove, to ensure consistent spacing of data in a spiral track. The walls of the groove are modulated in a consistent sinusoidal pattern, so that a drive can read

38、and compare it to an oscillator for precise rotation of the disc. This modulated pattern is called a wob- ble groove, because the walls of the groove appear to wobble from side to side. This signal is only used during recording, and therefore has no effect on the playback process. Among the DVD fami

39、ly of formats, only recordable media use wobble grooves. Dual Layer Discs Two information layers are separated by a thin transparent layer. Refer to Figure 11. The first layer is partially transparent. This allows the sec- ond layer to be read through the first layer. Both layers are read by control

40、ling the focus. There are two methods for reading the data of a Dual Layer disc, PTP and OTP. Refer to Figure 12. PTP is Parallel Track Path. That means the Lead In and Out Areas of the two layers correspond to each other. Each Lead In Area is on the inner portion of the disc, and the Lead Out Area

41、is on the outer portion of the disc. This is useful to link data between the layers. Figure 11 Dual Layer DVD 7 Figure 10 - Wobble Pregroove This allows instant access to the additional data or scene. OTP is Opposite Track Path. This method links the end of one layer to the begin- ning of the other.

42、 The Lead In Area is still on the inner portion of the disc. There is a Middle Track Area on both of the layers located on the outer portion of the layers. The Middle Track Area links the data on the two layers together. The Lead Out Area is on the second layer on the inner por- tion of the disc. Ca

43、pacity Because a stamped DVD can be Dual Layered and Double Sided, there are four different capac- ities. Refer to Figure 13. These capacities strict- ly pertain to raw data. The time available for Video and Audio has many extra factors that determine the length of time on each side or layer. The pi

44、cture complexity and the amount of movement in the picture affect compression and time on a disc. The number of languages affect the time on a disc. The type and quality of the Audio has an affect on the time also. It can be mono, stereo, or AC-3. Therefore, the media itself determines the capacity

45、in time on the disc. Figure 13 DVD Multi-Layered Capacities 8 Figure 12 PTP and OTP Layout Description The End User/Dealer Self Diagnostics work with- out the need for other equipment. Anumber of hardware tests are automatically executed to check for faults in the recorder. The diagnosis ends with a

46、 “FAIL” or “PASS” message. If the message “FAIL” appears on the display, an Error Code is displayed. If the message “PASS” appears, the tests have been executed success- fully. There can still be a failure in the recorder. The tests do not cover the complete unit. The following list describes the te

47、sts being preformed while the test number is being displayed on the Front Panel. To place the unit in the Self Test Mode, hold the Play pushbutton on the Front Panel while suppling AC power to the unit. The display counts down numerically the test it is performing. The following is a list of the tes

48、t displayed as: “Test Number” is displayed on the Front Panel “Name”of the test Description of the test 22 SdramWrR Checks all memory locations of the 4Mbyte SDRAM 21 HostdDramWrR Checks all the DRAM connected to the micro- computer on the Digital Board 20 HostdI2cNvram Checks the data line (SDA) an

49、d the clock line (SCL) of the I2C bus between the host decoder and NVRAM 19 SAA7118I2c Checks the interface between the Host I2C con- troller and the SAA7118 Video Input Processor 18 VideoEncI2c Checks the interface between the host I2C con- troller and Empress 17 AudioEncI2c Checks the I2C connection between the host decoder and Empress 16 AudioEncAccess Tests the HIO8 interface lines between the host decoder and the audio encoder 15 AudioEncSramAccess Checks the access of the SRAM by the audio encoder (address and data lines). 14 AudioEncSramWrR Tests the