Keithley_2000rep 电路图.pdf

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1、 Contains Servicing Information Model 2000 Multimeter Repair Manual RadioFans.CN 收音机爱 好者资料库 WARRANTY Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 3 years from date of shipment. Keithley Instruments, Inc. warrants the following i

2、tems for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes, and documentation. During the warranty period, we will, at our option, either repair or replace any product that proves to be defective. To exercise this warranty, write or call your local Keithley represe

3、ntative, or contact Keithley headquarters in Cleveland, Ohio. You will be given prompt assistance and return instructions. Send the product, transporta- tion prepaid, to the indicated service facility. Repairs will be made and the product returned, transportation prepaid. Repaired or replaced produc

4、ts are warranted for the balance of the original warranty period, or at least 90 days. LIMITATION OF WARRANTY This warranty does not apply to defects resulting from product modifi cation without Keithleys express writ- ten consent, or misuse of any product or part. This warranty also does not apply

5、to fuses, software, non- rechargeable batteries, damage from battery leakage, or problems arising from normal wear or failure to fol- low instructions. THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUD- ING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICU

6、LAR USE. THE REMEDIES PROVIDED HEREIN ARE BUYERS SOLE AND EXCLUSIVE REMEDIES. NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARIS- ING OUT OF THE USE OF ITS INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY I

7、NSTRU- MENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS OF REMOVAL AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PER- SON, OR DAMAGE TO PROPERTY. Keithley Instruments, Inc. 28775 Aurora

8、 Road Cleveland, OH 44139 440-248-0400 Fax: 440-248-6168 BELGIUM:Keithley Instruments B.V. Bergensesteenweg 709 B-1600 Sint-Pieters-Leeuw 02/363 00 40 Fax: 02/363 00 64 CHINA:Keithley Instruments China Yuan Chen Xin Building, Room 705 12 Yumin Road, Dewai, Madian Beijing 100029 8610-62022886 Fax: 86

9、10-62022892 FRANCE:Keithley Instruments Sarl B.P. 60 3, alle des Garays 91122 Palaiseau Cdex 01 64 53 20 20 Fax: 01 60 11 77 26 GERMANY:Keithley Instruments GmbH Landsberger Strasse 65 D-82110 Germering 089/84 93 07-40 Fax: 089/84 93 07-34 GREAT BRITAIN: Keithley Instruments Ltd The Minster 58 Portm

10、an Road Reading, Berkshire RG30 1EA 0118-9 57 56 66 Fax: 0118-9 59 64 69 INDIA:Keithley Instruments GmbH Flat 2B, WILOCRISSA 14, Rest House Crescent Bangalore 560 001 91-80-509-1320/21 Fax: 91-80-509-1322 ITALY:Keithley Instruments s.r.l. Viale S. Gimignano, 38 20146 Milano 02/48 30 30 08 Fax: 02/48

11、 30 22 74 NETHERLANDS:Keithley Instruments B.V. Postbus 559 4200 AN Gorinchem 0183-635333 Fax: 0183-630821 SWITZERLAND:Keithley Instruments SA Kriesbachstrasse 4 8600 Dbendorf 01-821 94 44 Fax: 01-820 30 81 TAIWAN:Keithley Instruments Taiwan 1 Fl. 85 Po Ai Street Hsinchu, Taiwan, R.O.C. 886-3572-907

12、7 Fax: 886-3572-9031 6/99 RadioFans.CN 收音机爱 好者资料库 Model 2000 Multimeter Repair Manual 1995, Keithley Instruments, Inc. All rights reserved. Cleveland, Ohio, U.S.A. Second Printing, March 1997 Document Number: 2000-902-01 Rev. B RadioFans.CN 收音机爱 好者资料库 Manual Print History The print history shown bel

13、ow lists the printing dates of all Revisions and Addenda created for this manual. The Revision Level letter increases alphabetically as the manual undergoes sub- sequent updates. Addenda, which are released between Revisions, contain important change in- formation that the user should incorporate im

14、mediately into the manual. Addenda are numbered sequentially. When a new Revision is created, all Addenda associated with the previous Revision of the manual are incorporated into the new Revision of the manual. Each new Revision includes a revised copy of this print history page. Revision A (Docume

15、nt Number 2000-902-01).May 1995 Revision B (Document Number 2000-902-01).March 1997 All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc. Other brand names are trademarks or registered trademarks of their respective holders. Safety Precautions The following

16、 safety precautions should be observed before using this product and any associated instrumen- tation. Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous conditions may be present. This product is intended for use by qua

17、lifi ed personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury. Read the operating information carefully before using the product. The types of product users are: Responsible body is the individual or group responsible for the use and mai

18、ntenance of equipment, and for en- suring that operators are adequately trained. Operators use the product for its intended function. They must be trained in electrical safety procedures and proper use of the instrument. They must be protected from electric shock and contact with hazardous live cir-

19、 cuits. Maintenance personnel perform routine procedures on the product to keep it operating, for example, setting the line voltage or replacing consumable materials. Maintenance procedures are described in the manual. The procedures explicitly state if the operator may perform them. Otherwise, they

20、 should be performed only by ser- vice personnel. Service personnel are trained to work on live circuits, and perform safe installations and repairs of products. Only properly trained service personnel may perform installation and service procedures. Exercise extreme caution when a shock hazard is p

21、resent. Lethal voltage may be present on cable connector jacks or test fi xtures. The American National Standards Institute (ANSI) states that a shock hazard exists when voltage levels greater than 30V RMS, 42.4V peak, or 60VDC are present. A good safety practice is to expect that hazardous voltage

22、is present in any unknown circuit before measuring. Users of this product must be protected from electric shock at all times. The responsible body must ensure that users are prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential human c

23、ontact. Product users in these circumstances must be trained to protect themselves from the risk of electric shock. If the circuit is capable of operating at or above 1000 volts, no conductive part of the circuit may be exposed. As described in the International Electrotechnical Commission (IEC) Sta

24、ndard IEC 664, digital multimeter measuring circuits (e.g., Keithley Models 175A, 199, 2000, 2001, 2002, and 2010) measuring circuits are In- stallation Category II. All other instruments signal terminals are Installation Category I and must not be con- nected to mains. Do not connect switching card

25、s directly to unlimited power circuits. They are intended to be used with imped- ance limited sources. NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protective devices to limit fault current and voltage to the card. Before operating an instru

26、ment, make sure the line cord is connected to a properly grounded power receptacle. Inspect the connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use. For maximum safety, do not touch the product, test cables, or any other instruments while power is applied

27、to the circuit under test. ALWAYS remove power from the entire test system and discharge any capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers. Do not touch any object that coul

28、d provide a current path to the common side of the circuit under test or power line (earth) ground. Always make measurements with dry hands while standing on a dry, insulated surface ca- pable of withstanding the voltage being measured. Do not exceed the maximum signal levels of the instruments and

29、accessories, as defi ned in the specifi cations and operating information, and as shown on the instrument or test fi xture panels, or switching card. When fuses are used in a product, replace with same type and rating for continued protection against fi re hazard. Chassis connections must only be us

30、ed as shield connections for measuring circuits, NOT as safety earth ground connections. If you are using a test fi xture, keep the lid closed while power is applied to the device under test. Safe operation requires the use of a lid interlock. If a screw is present, connect it to safety earth ground

31、 using the wire recommended in the user documen- tation. The symbol on an instrument indicates that the user should refer to the operating instructions located in the manual. The symbol on an instrument shows that it can source or measure 1000 volts or more, including the com- bined effect of normal

32、 and common mode voltages. Use standard safety precautions to avoid personal contact with these voltages. The WARNING heading in a manual explains dangers that might result in personal injury or death. Always read the associated information very carefully before performing the indicated procedure. T

33、he CAUTION heading in a manual explains hazards that could damage the instrument. Such damage may invalidate the warranty. Instrumentation and accessories shall not be connected to humans. Before performing any maintenance, disconnect the line cord and all test cables. To maintain protection from el

34、ectric shock and fi re, replacement components in mains circuits, including the power transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable national safety approvals, may be used if the rating and type are the same. Other components th

35、at are not safety related may be purchased from other suppliers as long as they are equivalent to the original component. (Note that selected parts should be purchased only through Keithley Instruments to maintain accu- racy and functionality of the product.) If you are unsure about the applicabilit

36、y of a replacement component, call a Keithley Instruments offi ce for information. To clean the instrument, use a damp cloth or mild, water based cleaner. Clean the exterior of the instrument only. Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument.

37、! Table of Contents 1 Routine Maintenance Introduction.1-2 Setting line voltage and replacing fuse.1-2 AMPS fuse replacement.1-4 2 Troubleshooting Introduction.2-2 Repair considerations.2-3 Power-on test .2-3 Front panel tests.2-4 Principles of operation.2-5 Display board checks.2-11 Power supply ch

38、ecks.2-11 Digital circuitry checks.2-12 Analog signal switching states.2-13 Built-In Test overview .2-18 Built-In Test documentation .2-22 3 Disassembly Introduction.3-2 Handling and cleaning.3-3 Static sensitive devices .3-4 Assembly drawings.3-4 Case cover removal.3-5 Changing trigger link lines .

39、3-6 Motherboard removal .3-7 Front panel disassembly .3-8 Main CPU fi rmware replacement.3-9 Removing power components .3-10 Instrument re-assembly.3-12 4 Replaceable Parts Introduction.4-2 Parts lists.4-2 Ordering information.4-2 Factory service.4-3 Component layouts.4-3 A Specifi cations .A-1 List of Illustrations 1 Routine Maintenance Power module.1-3 2 Troubleshooting Power supply block diagram.2-6 Digital circuitry block diagram.2-7 Analog circuitry block diagram.2-9 3 Disassembly Trigger link line connections.3-6 List of Tables 1 Routine Maintenance Fuse rating .