Philips-DVDR-75-Service-Manual 电路图 维修手册.pdf

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1、Philips DVDR75 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 Technic

2、ian. There are two versions of the DVDR75. The first four digits of the Product Number indicates the version. The Product Number is similar to a Serial Number. It will read VN02 or VN04. The VN04 is the newer of the two. The VN04 uses an updated Digital Board that contains the functionality of the D

3、VIO Board. When there are two versions of a circuit, the title to the section will have one or the other in the title, VN02 or VN04. The first portion of this manual contains a basic description of disc based data playback and recording technologies. Self Diagnostics are included to aid in troublesh

4、ooting. Technical Descriptions of the circuitry are followed by a Troubleshooting Section. The DVDR75 is the forth generation in a line of DVD recorders. Recordings can be made from broadcast transmissions, and from other analog or digital sources. The DVDRW format allows the user to record and eras

5、e a disc many times. The recorded discs will play on most existing and future DVD players. The DVDR75 has a connection for DV or Digital camcorders via an I-Link or Firewire connection. This con- nection technically is called an IEEE 1394 con- nection. This machine records on 4.7Gbyte DVD+R and DVD+

6、RW discs. This machine uses a real-time MPEG2 Variable Bit Rate, VBR, Video encoder. The DVDR75 plays 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 B

7、ase Corrector, Digital Audio output (DTS, AC- 3, MPEG, PCM), TruSurround for 3D sound, Zoom + Perfect 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 DVDR75, when first hooked up, needs to get informati

8、on from the user about what lan- guage and what local broadcast system the unit is going to operate 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

9、 again while hold- ing the STANDBY-ON button. DVD Basics Philips with nine other manufacturers chose a format specification for DVDR and RW on March 16, 2001. This format uses Real Time recording. Its recording is compatible with DVD-Video, and DVD ROM. The data blocks use lossless linking. The phys

10、ical layout matches very closely to that of a DVD ROM. See Figure 1. It also uses Direct Overwrite when a RW disc is used. Figure 1 DVD ROM Disc 1 RadioFans.CN 收音机爱 好者资料库 Laser Technology The DVD and CD share much of their technolo- gy. We will start with CDs and work our way to the DVD. CDs use a r

11、ed 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 innermost tracks of the CD and reads outward. At the begi

12、nning of the disc is the Table of Contents. At the bottom of the Light Pen are Monitoring Diodes. The Monitoring Diodes provide information about focus and tracking. Data is retrieved from the disc in the form of pulses of light reflecting from the disc. The pulses are created by Pits in the Reflect

13、ive Layer of the disc. The Pits reflect less light than the intact surface of the Reflective Layer, called Lands. The data is binary. A1 is generated when the light transitions from bright to dim and dim to bright. The time between is a series of zeros determined by the data rate. Disc Mechanical La

14、yout The CD is a plastic disc 120mm in diameter, with a thickness of 1.2mm. Refer to Figure 3. It has a silver colored Reflective Layer. The maximum playing time for a music recording on a Compact Disc, CD, is 74 Min. Figure 2 CD Laser Operation 2 Figure 3 - CD Disc RadioFans.CN 收音机爱 好者资料库 The CD is

15、 less vulnerable to damage than an analog record. That does not mean it does not have to be treated with care. Dirt and heavy scratches can interfere with playability. As shown in Figure 4, the CD is subdivided into three parts: the Lead In Track, the Program Area, and the Lead Out Area. These three

16、 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. The Data on the disc is recorded on a spiral shaped track

17、 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 form for a metal cast. The metal cast is used to stamp a n

18、ickel 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. Figure 4 - The Disc Figure 5 - Creating a CD 3 Read Process The Servo circuit is responsible for focusing the laser and moving the L

19、ight Pen to follow the spi- raling tracks on the rotating disc. The digital High 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 rotating disc is servo controlled to keep the RAM half fu

20、ll. The analog signals are amplified and sent to the output 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. There are three possible states of a disc: a blank disc, a

21、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 Figure 6. Apartially recorded discs Information Area has four s

22、ections: 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 or finalized discs Information Area has three sections: A lea

23、d 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 the disc. This is polycarbonant for DVD+Rs and organic dye

24、material for DVD+RWs. This spiral Pre-groove is for the Servo circuit to provide a mechanical reference during recording. The dye based RW recordable layer provides a reflectivity of 40% light return and 70% light return. 40 percent reflectivity rep- resents Pits and the 70% represent the Lands. Rec

25、ord Process The record process shares most of its mechani- Figure 6 APartially Recorded Disc. Figure 7 Fully Recorded or Finalized Disc 4 cal operation with that of the play process. The main difference is how the Servo is locked to the disc. The Servo follows the Pre-groove for Radial Tracking and

26、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, the laser arrives at a position where a Pit is to be forme

27、d. 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 read laser power to write laser power forms a pit and land pa

28、ttern 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 recordable layer is made up of an alloy of silver, indium, antimo

29、ny 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. 8mW is the playback laser power and 14mW is the record lase

30、r 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 stamped CD. Amajor difference of CDRWs from CDRs is the ability

31、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. This is done at X2 record- ing speed. The slower speed allow

32、s 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 Over writing combines the processes of erasing and writing. When the disc an

33、d 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 level rather than the playback level. Figure 8 Mechanical Layo

34、ut 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 technolo- gy, you will want to start with the information p

35、re- 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 layered discs. ADigital Versatile Disc, DVD, looks very simi

36、lar 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 of the big differences between DVDs and CDs are the Pit and

37、 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 glued back to back, producing 1.2mm total thickness. Figure 8

38、- 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 the recorder with the timing information needed to place th

39、e 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 and compare it to an oscillator for precise rotation of the

40、 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 family of formats, only recordable media use wobble grooves. Dua

41、l 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 controlling the focus. There are two methods for reading the data o

42、f 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 is on the outer portion of the disc. This is useful to link

43、data between the layers. 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. The Lead In Area is still on the Figure 11 Dual Layer DVD 7 Figure 10 - Wobble Pregroove inner portion of the disc.

44、 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. Capacity Because a stamped DVD can be Dual Layered and Double

45、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 picture complexity and the amount of movement in the picture a

46、ffect 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 in time on the disc. Figure 13 DVD Multi-Layered Capacities

47、8 Figure 12 PTP and OTP Layout Description The VN02 products have this feature. The End User/Dealer Self Diagnostics work without the need for other equipment. Anumber of hardware tests are automatically executed to check for faults in the recorder. The final test, number one, routes video to the Co

48、mposite Out jack. The sig- nal is a Pal Color bar signal. Most televisions will show the bars in B+W. This is dependent on the pull in range of the monitor, as the frequencies are shifted as compared to NTSC. The diagnosis ends with a “FAIL” or “PASS” message. If the message “FAIL” appears on the di

49、splay, 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 tests being performed 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 sup- pling AC power to the unit. The word BUSY appears on the display followed by test number. The display counts down numerically to test if it is performing.