LG-LRM519-mr-sm 维修电路原理图.pdf
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1、SERVICE MANUALLG LRM-519 DIGITALMEDIARECORDERSERVICE MANUALMODEL : LRM-519(RV7922M)CAUTIONBEFORE SERVICING THE UNIT, READ THE “SAFETYPRECAUTIONS”IN THIS MANUAL.MODEL : LRM-519(RV7922M)SERVICE MANUALP/NO : 3829RVN004LAUGUST, 2005RadioFans.CN 收音机爱 好者资料库1-1SECTION 1SUMMARYCONTENTSPRODUCT SAFETY SERVICI
2、NG GUIDELINES FOR VIDEO PRODUCTS.1-2SERVICING PRECAUTIONS.1-3INTRODUCTION .1-4SPECIFICATIONS.1-5SYSTEM S/W UPGRADE.1-7TEST S/W .1-8RadioFans.CN 收音机爱 好者资料库1-2IMPORTANT SAFETY NOTICEThis manual was prepared for use only by properly trained audio-video servicetechnicians.When servicing this product, un
3、der no circumstances should the originaldesign be modified or altered without permission from Zenith ElectronicsCorporation. All components should be replaced only with types identical tothose in the original circuit and their physical location, wiring and lead dressmust conform to original layout u
4、pon completion of repairs.Special components are also used to prevent x-radiation, shock and fire haz-ard. These components are indicated by the letter “x” included in their compo-nent designators and are required to maintain safe performance. No deviationsare allowed without prior approval by Zenit
5、h Electronics Corporation.Circuit diagrams may occasionally differ from the actual circuit used. This way,implementation of the latest safety and performance improvement changesinto the set is not delayed until the new service literature is printed.CAUTION: Do not attempt to modify this product in a
6、ny way. Never performcustomized installations without manufacturers approval. Unauthorized modi-fications will not only void the warranty, but may lead to property damage oruser injury.Service work should be performed only after you are thoroughly familiar withthese safety checks and servicing guide
7、lines.GRAPHIC SYMBOLSThe exclamation point within an equilateral triangle is intended toalert the service personnel to important safety information in theservice literature.The lightning flash with arrowhead symbol within an equilateral tri-angle is intended to alert the service personnel to the pre
8、sence ofnoninsulated “dangerous voltage” that may be of sufficient magni-tude to constitute a risk of electric shock.The pictorial representation of a fuse and its rating within an equi-lateral triangle is intended to convey to the service personnel thefollowing fuse replacement caution notice: CAUT
9、ION: FOR CONTINUED PROTECTION AGAINST RISKOF FIRE, REPLACE ALL FUSES WITH THE SAME TYPE ANDRATING AS MARKED NEAR EACH FUSE.SERVICE INFORMATIONWhile servicing, use an isolation transformer for protection from AC line shock.After the original service problem has been corrected, make a check of the fol
10、-lowing:FIRE AND SHOCK HAZARD1. Be sure that all components are positioned to avoid a possibility of adjacentcomponent shorts. This is especially important on items trans-ported to andfrom the repair shop.2. Verify that all protective devices such as insulators, barriers, covers, shields,strain reli
11、efs, power supply cords, and other hardware have been reinstalledper the original design. Be sure that the safety purpose of the polarized lineplug has not been defeated.3. Soldering must be inspected to discover possible cold solder joints, soldersplashes, or sharp solder points. Be certain to remo
12、ve all loose foreign par-ticles.4. Check for physical evidence of damage or deterioration to parts and compo-nents, for frayed leads or damaged insulation (including the AC cord), andreplace if necessary.5. No lead or component should touch a high current device or a resistor ratedat 1 watt or more.
13、 Lead tension around protruding metal surfaces must beavoided.6. After reassembly of the set, always perform an AC leakage test on allexposed metallic parts of the cabinet (the channel selector knobs, antennaterminals, handle and screws) to be sure that set is safe to operate withoutdanger of electr
14、ical shock. DO NOT USE A LINE ISOLATION TRANS-FORMER DURING THIS TEST. Use an AC voltmeter having 5000 ohms pervolt or more sensitivity in the following manner: Connect a 1500 ohm, 10watt resistor, paralleled by a .15 mfd 150V AC type capacitor between aknown good earth ground water pipe, conduit, e
15、tc.) and the exposed metal-lic parts, one at a time. Measure the AC voltage across the combination of1500 ohm resistor and .15 mfd capacitor. Reverse the AC plug by using anon-polarized adaptor and repeat AC voltage measurements for eachexposed metallic part. Voltage measured must not exceed 0.75 vo
16、lts RMS.This corresponds to 0.5 milliamp AC. Any value exceeding this limit consti-tutes a potential shock hazard and must be corrected immediately.TIPS ON PROPER INSTALLATION1. Never install any receiver in a closed-in recess, cubbyhole, or closely fittingshelf space over, or close to, a heat duct,
17、 or in the path of heated air flow.2. Avoid conditions of high humidity such as: outdoor patio installations wheredew is a factor, near steam radiators where steam leakage is a factor, etc.3. Avoid placement where draperies may obstruct venting. The customershould also avoid the use of decorative sc
18、arves or other coverings thatmight obstruct ventilation.4. Wall- and shelf-mounted installations using a commercial mounting kit mustfollow the factory-approved mounting instructions. A product mounted to ashelf or platform must retain its original feet (or the equivalent thickness inspacers) to pro
19、vide adequate air flow across the bottom. Bolts or screwsused for fasteners must not touch any parts or wiring. Perform leakage testson customized installations.5. Caution customers against mounting a product on a sloping shelf or in a tilt-ed position, unless the receiver is properly secured.6. A p
20、roduct on a roll-about cart should be stable in its mounting to the cart.Caution the customer on the hazards of trying to roll a cart with small cast-ers across thresholds or deep pile carpets.7. Caution customers against using extension cords. Explain that a forest ofextensions, sprouting from a si
21、ngle outlet, can lead to disastrous conse-quences to home and family.A.C. Voltmeter1500 OHM10 WATTPlace this probeon each exposedmetal part.Good Earth Groundsuch as the WaterPipe, Conduit, etc.0.15uFPRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS1-3SERVICING PRECAUTIONSCAUTION: Before servici
22、ng the HD/SD PERSONAL VIDEORECORDER & RECEIVER WITH GEMSTAR covered bythis service data and its supplements and addends, read andfollow the SAFETY PRECAUTIONS. NOTE: if unforeseencircumstances create conflict between the following servic-ing precautions and any of the safety precautions in this pub-
23、lications, always follow the safety precautions.Remember Safety First:General Servicing Precautions1. Always unplug the HD/SD PERSONALVIDEORECORDER & RECEIVER WITH GEMSTAR AC powercord from the AC power source before:(1)Removing or reinstalling any component, circuit board, module, or any other asse
24、mbly.(2)Disconnecting or reconnecting any internal electricalplug or other electrical connection.(3)Connecting a test substitute in parallel with an elec-trolytic capacitor.Caution: A wrong part substitution or incorrect polarity installation of electrolytic capacitors may resultin an explosion haza
25、rd.2. Do not spray chemicals on or near this HD/SD PERSON-AL VIDEO RECORDER & RECEIVER WITH GEMSTARor any of its assemblies.3. Unless specified otherwise in this service data, cleanelectrical contacts by applying an appropriate contact cleaning solution to the contacts with a pipe cleaner,cotton-tip
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