Philips dvdr 985 service manual
This is the 119 pages manual for philips dvdr 985 service manual.
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Introduction This Manual is intended for use by the Service Technician. 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 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 DVDR985 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 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 Base Correcter, 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 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 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 chose 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. SeeFigure 1. It also uses Direct Overwrite 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 innermost 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 Disc 1
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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 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 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