Ricoh AC205, B273 Service Manual

B273

SERVICE MANUAL

002544MIU

B273

SERVICE MANUAL

B273

SERVICE MANUAL

002544MIU

It is the reader's responsibility when discussing the information contained within this document to maintain a level of confidentiality that is in the best interest of Ricoh Corporation and its member companies.

NO PART OF THIS DOCUMENT MAY BE REPRODUCED IN ANY

FASHION AND DISTRIBUTED WITHOUT THE PRIOR

PERMISSION OF RICOH CORPORATION.

ll product names, domain names or product illustrations, including desktop images, used in this document are trademarks, registered trademarks or the property of their respective companies. They are used throughout this book in an informational or editorial fashion only and for the benefit of such companies. No such use, or the use o

any trade name, or web site is intended to convey endorsement or othe

affiliation with Ricoh products.

The Service Manual contains information regarding service techniques, procedures,

rocesses and spare parts of office equipmen

distributed by Ricoh Corporation. Users of this manual should be either service trained o

certified by successfully completing a Ricoh Technical Training Program.

Untrained and uncertified users utilizin

information contained in this service manual to repair or modify Ricoh equipment risk persona

injury, damage to property or loss of warrant

rotection.

Ricoh Corporation

WARNING

LEGEND

PRODUCT CODE COMPANY

GESTETNER LANIER RICOH SAVIN

B273 DSm520pf AC122 AC205 AC205

DOCUMENTATION HISTORY

REV. NO. DATE COMMENTS

09/2005 Original Printing

SM i B273

B273

TABLE OF CONTENTS

INSTALLATION

1. INSTALLATION............................................................................ 1-1

PREVENTIVE MAINTENANCE

2. PREVENTIVE MAINTENANCE.................................................... 2-1

2.1 PM INTERVALS ........................................................................................ 2-1

REPLACEMENT AND ADJUSTMENT

3. REPLACEMENT AND ADJUSTMENT ........................................ 3-1

3.1 GENERAL PRECAUTIONS.......................................................................3-1

3.1.1 SERVICING THE MACHINE ............................................................3-1

3.1.2 RELEASING PLASTIC LATCHES....................................................3-1

3.2 COVERS ...................................................................................................3-2

3.2.1 REAR COVER..................................................................................3-2

3.2.2 SIDE COVERS .................................................................................3-3

Right Cover...........................................................................................3-3

Left Cover ............................................................................................. 3-4

3.2.3 FRONT COVER................................................................................3-5

3.3 SCANNER ASSEMBLY............................................................................. 3-6

3.3.1 REASSEMBLING THE SCANNER ASSEMBLY ............................3-14

3.4 ADF MOTOR ASSEMBLY.......................................................................3-15

3.5 OPERATION PANEL...............................................................................3-18

3.6 MIDDLE COVER AND EXIT ROLLER ....................................................3-20

3.7 CONTROLLER SHIELD ASSEMBLY......................................................3-22

3.8 ENGINE SHIELD ASSEMBLY AND EXIT BOARD .................................3-24

3.8.1 ENGINE SHIELD............................................................................3-24

3.8.2 EXIT BOARD..................................................................................3-26

3.9 SMPS AND LIU ....................................................................................... 3-27

3.10 FUSING UNIT........................................................................................3-29

3.10.1 FUSING UNIT ASSEMBLY ..........................................................3-29

3.10.2 THERMOSTAT.............................................................................3-30

3.10.3 FUSING LAMP .............................................................................3-30

3.10.4 STRIPPER PAWLS ......................................................................3-31

Reassembling the Fusing Unit ............................................................3-32

Note. ................................................................................................... 3-33

3.10.5 THERMISTOR..............................................................................3-34

3.11 FAN .......................................................................................................3-35

3.12 LSU .......................................................................................................3-36

B273 ii SM

3.13 CRUM BOARD ...................................................................................... 3-37

3.14 DRIVE ASSEMBLY ...............................................................................3-38

3.15 COVER MID-FRONT.............................................................................3-39

3.16 TRANSFER ASSEMBLY.......................................................................3-40

3.17 FEED ASSEMBLY.................................................................................3-42

3.18 PICK-UP ASSEMBLY AND SOLENOID................................................ 3-45

3.18.1 PICK-UP ASSEMBLY...................................................................3-45

3.18.2 SOLENOID ...................................................................................3-46

3.18.3 BY-PASS PICK-UP ROLLER AND PAPER FEED

UNIT PICK-UP ROLLER. .............................................................3-47

By-pass pick-up roller .........................................................................3-47

Paper Feed Unit Pick-up Roller ..........................................................3-48

TROUBLESHOOTING

4. TROUBLESHOOTING ................................................................. 4-1

4.1 PAPER PATH............................................................................................4-1

4.1.1 COPY/SCAN DOCUMENT PATH ....................................................4-2

Scanner ................................................................................................4-2

Engine...................................................................................................4-3

4.1.2 PRINTER PAPER PATH ..................................................................4-4

4.2 PAPER JAM CONDITIONS....................................................................... 4-5

Jam0 (Paper Feed Area) Jam1 (Fusing/Toner Cartridge)................4-5

Jam2 (Paper Exit Area) By-pass Jam (By-pass Tray).......................4-5

4.2.1 CLEARING DOCUMENT JAMS (ADF).............................................4-6

ADF Input Misfeed ................................................................................4-6

ADF Exit Misfeed ..................................................................................4-7

ADF Roller Misfeed...............................................................................4-7

4.2.2 JAM0 (PAPER FEED AREA)............................................................4-8

4.2.3 JAM1 (FUSING AREA OR AROUND THE TONER

CARTRIDGE AREA).........................................................................4-9

4.2.4 JAM2 (PAPER EXIT AREA) ...........................................................4-10

4.2.5 BY-PASS TRAY JAM .....................................................................4-11

4.3 PAPER FEED PROBLEMS.....................................................................4-12

4.3.1 INCORRECT PRINT POSITION ....................................................4-12

4.3.2 JAM 0 .............................................................................................4-12

4.3.3 JAM 1 .............................................................................................4-13

4.3.4 JAM 2 .............................................................................................4-13

4.3.5 MULTI-FEEDING............................................................................4-14

4.3.6 PAPER IN THE FUSING UNIT.......................................................4-14

4.3.7 PAPER BECOMES ROLLED AROUND THE OPC DRUM ............4-15

4.3.8 DEFECTIVE ADF ...........................................................................4-15

4.4 MACHINE MALFUNCTIONS...................................................................4-16

4.4.1 LCD DISPLAY DEFECTIVE ...........................................................4-16

4.4.2 DEFECTIVE CONTROL PANEL ....................................................4-16

4.4.3 FUSING GEAR MELTS (OVERHEATS).........................................4-16

4.4.4 PAPER EMPTY 1 ...........................................................................4-17

4.4.5 PAPER EMPTY 2 ...........................................................................4-17

SM iii B273

4.4.6 COVER OPEN 1............................................................................. 4-17

4.4.7 COVER OPEN 2............................................................................. 4-18

4.4.8 DEFECTIVE MOTOR OPERATION ...............................................4-18

4.4.9 NO POWER....................................................................................4-18

4.4.10 PRINTED VERTICAL LINES ARE CURVED................................4-19

4.5 PRINTING QUALITY PROBLEMS .......................................................... 4-20

4.5.1 INCORRECT PRINT POSITION ....................................................4-20

4.5.2 VERTICAL WHITE LINE.................................................................4-20

4.5.3 HORIZONTAL BLACK BANDS ......................................................4-21

4.5.4 BLACK/WHITE SPOTS .................................................................. 4-21

4.5.5 LIGHT IMAGE ................................................................................4-22

4.5.6 DARK/BLACK IMAGE ....................................................................4-22

4.5.7 UNEVEN DENSITY ........................................................................4-23

4.5.8 BACKGROUND..............................................................................4-23

4.5.9 GHOST 1........................................................................................4-24

4.5.10 GHOST 2......................................................................................4-24

4.5.11 GHOST 3......................................................................................4-25

4.5.12 GHOST 4......................................................................................4-25

4.5.13 MARKS ON FRONT OF PAGE ....................................................4-26

4.5.14 MARKS ON BACK OF PAGE.......................................................4-26

4.5.15 BLANK PAGE 1............................................................................4-27

4.5.16 BLANK PAGE 2............................................................................4-27

4.6 FAX AND PHONE PROBLEMS ..............................................................4-28

4.6.1 NO DIAL TONE ..............................................................................4-28

4.6.2 DEFECTIVE MF DIAL ....................................................................4-28

4.6.3 DEFECTIVE FAX FORWARD/RECEIVE .......................................4-29

4.6.4 DEFECTIVE FAX FORWARD ........................................................4-29

4.6.5 DEFECTIVE FAX RECEIVE 1........................................................4-29

4.6.6 DEFECTIVE FAX RECEIVE 2........................................................4-30

4.6.7 DEFECTIVE FAX RECEIVE 3........................................................4-30

4.6.8 DEFECTIVE FAX RECEIVE 4........................................................4-30

4.6.9 DEFECTIVE AUTOMATIC RECEIVING.........................................4-30

4.7 COPY PROBLEMS .................................................................................4-31

4.7.1 WHITE COPY.................................................................................4-31

4.7.2 BLACK COPY.................................................................................4-31

4.7.3 UNUSUAL NOISE ..........................................................................4-31

4.7.4 DEFECTIVE IMAGE QUALITY.......................................................4-31

4.8 SCANNING PROBLEMS......................................................................... 4-32

4.8.1 PC SCANNING PROBLEMS..........................................................4-32

4.8.2 POOR QUALITY OF SCANNED IMAGES .....................................4-32

4.9 ERROR MESSAGES ..............................................................................4-33

4.10 TONER CARTRIDGE............................................................................4-36

4.10.1 TONER CARTRIDGE PRECAUTIONS ........................................ 4-36

4.10.2 REDISTRIBUTING TONER..........................................................4-37

4.10.3 TONER CARTRIDGE ERROR MESSAGES ................................4-38

4.10.4 TONER CARTRIDE DETAILS......................................................4-39

4.11 SOFTWARE PROBLEMS .....................................................................4-43

4.11.1 PRINTER DOES NOT OPERATE CORRECTLY 1 ......................4-43

4.11.2 PRINTER DOES NOT OPERATE CORRECTLY 2 ......................4-44

B273 iv SM

4.11.3 ABNORMAL PRINTING ...............................................................4-45

4.11.4 SPOOL ERROR ...........................................................................4-45

How to Delete Data in the Spool Manager..........................................4-45

4.12 NETWORK PROBLEMS .......................................................................4-46

4.12.1 GENERAL PROBLEMS................................................................4-46

4.12.2 WINDOWS PROBLEMS...............................................................4-47

4.12.3 SYNCTHRU INSTALLATION PROBLEMS ..................................4-48

SERVICE PROGRAM MODE

5. SERVICE PROGRAM MODE....................................................... 5-1

5.1 TECH MODE .............................................................................................5-1

5.1.1 HOW TO ENTER TECH AND EXIT MODE......................................5-1

What you can do in Tech Mode ............................................................5-1

5.1.2 DATA SET-UP..................................................................................5-2

Send Level............................................................................................5-2

Dial Mode..............................................................................................5-2

Modem Speed ......................................................................................5-2

Error Rate ............................................................................................. 5-2

Notify Toner ..........................................................................................5-2

CLEAR ALL MEMORY .........................................................................5-3

Flash Upgrade ......................................................................................5-3

Silence Time .........................................................................................5-3

5.1.3 MACHINE TESTS.............................................................................5-4

Switch Test ...........................................................................................5-4

Modem Test..........................................................................................5-4

DRAM Test ...........................................................................................5-4

ROM Test .............................................................................................5-4

Pattern Test ..........................................................................................5-4

Shading Test.........................................................................................5-5

5.1.4 REPORTS ........................................................................................5-5

Protocol List ..........................................................................................5-5

System Data .........................................................................................5-5

5.2 USER MODE.............................................................................................5-6

5.3 FIRMWARE DOWNLOAD.........................................................................5-8

5.3.1 DOWNLOAD PROCEDURE.............................................................5-8

Printer Setting Utility Mode ...................................................................5-8

Web Image Monitor Mode.....................................................................5-9

5.3.2 FIRMWARE RECOVERY PROCEDURE ....................................... 5-11

5.4 ENGINE TEST MODE.............................................................................5-12

5.4.1 HOW TO ENTER ENGINE TEST MODE ....................................... 5-12

5.4.2 ENGINE TEST MODE TABLE........................................................5-13

Detailed Description (Engine Test Mode) ...........................................5-14

5.4.3 STATUS PRINT.............................................................................. 5-15

SM v B273

DETAILED DESCRIPTIONS

6. DETAILED DESCRIPTIONS ........................................................ 6-1

6.1 PRINTER COMPONENT LAYOUT ...........................................................6-1

6.1.1 FRONT VIEW ...................................................................................6-1

6.1.2 REAR VIEW .....................................................................................6-2

6.2 SYSTEM LAYOUT ....................................................................................6-3

6.2.1 PAPER FEED...................................................................................6-3

6.2.2 TRANSFER ASSEMBLY .................................................................. 6-3

6.2.3 DRIVE ASSEMBLY ..........................................................................6-3

6.2.4 FUSING ASSEMBLY........................................................................6-4

Thermostat............................................................................................6-4

Thermistor.............................................................................................6-4

Hot Roller..............................................................................................6-4

Pressure Roller .....................................................................................6-4

Safety Features ....................................................................................6-4

Safety Devices......................................................................................6-4

6.2.5 SCANNING UNIT .............................................................................6-5

CCD Module Specifications ..................................................................6-5

6.2.6 LASER SCANNING UNIT (LSU) ......................................................6-5

6.2.7 TONER CARTRIDGE ....................................................................... 6-6

6.2.8 NEW AIO DETECTION ....................................................................6-7

6.2.9 TONER END DETECTION...............................................................6-7

6.3 CONTROLLER .......................................................................................... 6-8

6.3.1 MAIN PBA ........................................................................................6-8

6.3.2 ASIC .................................................................................................6-9

Main Function Block..............................................................................6-9

6.3.3 MEMORY .........................................................................................6-9

6.3.4 FLASH MEMORY.............................................................................6-9

6.3.5 SDRAM.............................................................................................6-9

6.3.6 BATTERY BACKUP .........................................................................6-9

6.3.7 SENSOR INPUT CIRCUIT .............................................................6-10

Paper Empty Sensor...........................................................................6-10

By-pass Tray Sensor ..........................................................................6-10

Paper Feed Sensor............................................................................. 6-10

Paper Exit Sensor...............................................................................6-10

Cover Open Sensor ............................................................................6-10

DC Fan/Solenoid Driving ....................................................................6-10

Motor Driving ......................................................................................6-10

6.4 SMPS AND HVPS ...................................................................................6-11

6.4.1 HVPS..............................................................................................6-12

Transfer High Voltage (THV+) ............................................................6-12

Charge Voltage (MHV)........................................................................6-12

Cleaning Voltage (THV-).....................................................................6-12

Developing Voltage (DEV) ..................................................................6-12

Supply Voltage (SUP) ......................................................................... 6-13

OPC Ground ZENER Voltage.............................................................6-13

6.4.2 SMPS(SWITCHING MODE POWER SUPPLY) .............................6-14

B273 vi SM

1. AC Input............................................................................................6-14

2. Rated Output Power .........................................................................6-14

3. Power Consumption .........................................................................6-14

4. Length of Power cord........................................................................6-15

5. Power Switch:...................................................................................6-15

6. Feature .............................................................................................6-15

7. Environment Condition .....................................................................6-15

8. EMI Requirement..............................................................................6-15

9. Safety Requirement..........................................................................6-15

6.4.3 FUSING UNIT AC POWER CONTROL..........................................6-16

6.5 ENGINE...................................................................................................6-17

6.5.1 PAPER FEED.................................................................................6-17

Jam0 (feed area).................................................................................6-17

Jam1 (inside the machine)..................................................................6-17

Jam2 (exit area)..................................................................................6-17

6.5.2 DRIVE.............................................................................................6-18

6.5.3 TRANSFER ....................................................................................6-18

6.5.4 FUSING ..........................................................................................6-18

6.5.5 LASER SCANNING UNIT...............................................................6-19

6.6 OPERATION PANEL (OPE)....................................................................6-19

6.7 USB HOST ..............................................................................................6-20

6.8 FAX SECTION.........................................................................................6-20

6.8.1 MODEM..........................................................................................6-20

6.8.2 LIU PBA..........................................................................................6-20

SPECIFICATIONS

SPECIFICATIONS............................................................................. 7-1

1. GENERAL SPECIFICATIONS.....................................................................7-1

2. PHYSICAL SPECIFICATIONS....................................................................7-2

3. PRINT SPECIFICATIONS...........................................................................7-2

4. SCAN SPECIFICATIONS............................................................................7-3

5. COPY SPECIFICATIONS ...........................................................................7-4

6. TELEPHONE SPECIFICATIONS ................................................................7-5

7. FAX SPECIFICATIONS............................................................................... 7-6

8. SOFTWARE SPECIFICATIONS .................................................................7-7

9. PAPER SIZES/WEIGHTS ...........................................................................7-7

APPENDIX

BLOCK DIAGRAM ............................................................................ 8-1

CONNECTION DIAGRAM................................................................. 8-2

PRECAUTIONS

In order to prevent accidents and damage to the equipment, please read the following precautions before you service the machine.

SAFETY WARNING

1. Only qualified service engineers should service this machine. High voltages and lasers inside this product should be approached with caution.

2. Use only approved replacement parts There are no user serviceable parts inside this machine. Do not make any unauthorized changes or additions to the machine. This could cause the machine to malfunction, and create electric shock or fire hazards.

3. Laser Safety Statement: This machine is certified in the U.S. to conform to the requirements of DHHS 21 CFR, chapter 1 Subchapter J for Class 1(1) laser products and elsewhere. It is certified as a Class I laser product conforming to the requirements of IEC 825. Class I laser products are not considered to be hazardous. The laser system and printer are designed to prevent access to laser radiation during normal operation, user maintenance, or prescribed service activities.

Never operate or service the printer with the protective cover removed from

Laser/Scanner assembly. The reflected beam can damage your eyes. When using this product, these basic safety precautions should always be followed to reduce risk of fire, electric shock, and injury to persons.

WARNING

SAFETY PRECAUTIONS

TOXIC MATERIALS

This product contains toxic materials that could cause illness if ingested.

1. If the LCD control panel is damaged, it is possible for the liquid inside to leak out. This liquid is toxic and contact with skin should be avoided. Wash any splashes from eyes or skin immediately for 15 minutes under running water, and contact a doctor. See a doctor immediately if the liquid gets into the mouth or is swallowed.

2. Keep toner cartridges away from children. The toner powder contained in the toner cartridge may be harmful if swallowed. Contact a doctor immediately if toner powder is swallowed.

ELECTRIC SHOCK AND FIRE SAFETY PRECAUTIONS

Failure to adhere to the following instructions could cause electric shock or cause a fire.

1. Use only the specified voltage to power this machine. Failure to do so could damage the machine and cause a fire or electric shock.

2. Use only the power cable supplied with this machine. Use of an incorrectly specified cable could cause the cable to overheat and potentially cause a fire.

3. Do not overload the power socket. This could lead to overheating of the cables inside the wall and could lead to a fire.

4. Do not allow water or other liquids to spill into the machine. This can cause electric shock. Do not let paper clips, pins, or other foreign objects fall into the machine. These could cause a short circuit leading to an electric shock or fire hazard. If foreign objects fall into the machine, power off the machine and disconnect the power cord from the wall outlet immediately.

5. Never touch the plugs on either end of the power cable with wet hands. This can cause electric shock.

6. Remove the power plug from the wall socket when servicing the printer.

7. Use caution when you insert or remove the power plug. The power plug must be inserted completely. Otherwise, a poor contact could cause overheating and lead to a fire. (When removing the power plug, grip the plug firmly and pull.)

8. Do not allow the power cable to become twisted or bent sharply around corners. Do not place objects on top of the power cable. If the power cable is damaged, it could overheat and cause a fire. Exposed cables could cause an electric shock. Replace a damaged power cable immediately. Do not reuse or repair a damaged cable. Additionally, some chemicals can attack the coating on the power cable, weakening the cover or exposing cables causing fire and shock risks.

9. Ensure that the power sockets and plugs are not cracked or broken in any way. Repair such defects immediately. Take care not to cut or damage the power cable or plugs when moving the machine.

10. Use caution during thunder or lightening storms. Disconnect the machine from

the power source when such weather conditions are expected. Do not touch

the machine or the power cord if it is still connected to the wall socket in these weather conditions.

11. Avoid damp or dusty areas. Install the machine in a clean, well-ventilated location. Do not position the machine near a humidifier. Dampness and dust build-up inside the machine can lead to overheating and cause a fire.

12. Do not position the machine in direct sunlight. This will cause the temperature inside the machine to rise, possibly leading to machine failure and, in extreme conditions, could lead to a fire.

13. Do not insert metal objects into the machine through the ventilator fan or other part of the casing. This could create contact with a high voltage conductor inside the machine and cause an electric shock.

HANDLING PRECAUTIONS

The following instructions are for your own personal safety, to avoid injury and to prevent damage to the machine.

1. Ensure that the machine is installed on a level surface, capable of supporting its weight. Failure to do so could cause the machine to tip or fall.

2. Avoid placing fingers or hair in close proximity to any rollers, gears, or fans within this machine while the machine is in operation.

3. Do not place any small metal objects, containers of water, chemicals, or other liquids close to the machine. This can cause damage, shock, or fire if spilled into the machine.

4. Do not install the machine in areas with high dust or moisture levels, beside open windows, or close to a humidifier or heater.

5. Do not place candles, burning cigarettes, etc. on the machine. A fire may occur.

ASSEMBLY/DISASSEMBLY PRECAUTIONS

Replace with approved replacement parts only. Take care to note the exact location of components and correct cable routing before you disassemble any part of the machine. Ensure all parts and cables are replaced correctly. Perform the following procedures before you disassemble the machine or replace any parts:

1. Check the contents of the machine memory and make a note of any user settings. These will be erased if the main board or network card is replaced.

2. Ensure that power is disconnected before you service or replace any electrical parts.

3. Disconnect interface cables and power cables.

4. Use only approved spare parts. Ensure that part number, product name, voltages, current and/or temperature rating

are correct.

5. When removing or re-fitting any parts, do not use excessive force (especially when fitting screws into plastic).

6. Take care not to drop any small parts into the machine.

7. Handling of the OPC Drum:

• The OPC Drum can be damaged if it is exposed to light.

• Take care not to expose the OPC Drum to direct sunlight, fluorescent, or incandescent lighting. Exposure for as little as 5 minutes can damage the surface’s photoconductive properties and will result in print quality degradation. Remove the OPC Drum and store it in a black bag or other lightproof container. Take care when working with the covers (especially the top cover), as light can be admitted to the OPC area and can damage the OPC Drum.

• Take care not to scratch the green surface of OPC Drum. If the green surface of the OPC Drum is scratched or touched, the print quality will be compromised.

CAUTION1.TIF

Caution2.tif

ESD PRECAUTIONS

Certain semiconductor devices can be easily damaged by static electricity. Such components are commonly called “Electro-statically Sensitive (ES) Devices”, or ESDs. Examples of typical ESDs are: integrated circuits, some field-effect transistors, and semiconductor “chip” components.

The techniques outlined below should be followed to help reduce the incidence of component damage caused by static electricity.

CAUTION

Ensure that no power is applied to the chassis or circuit, and observe all other safety precautions.

1. Immediately before handling a semiconductor component or semiconductorequipped assembly, drain any electrostatic charge on your body by touching a known earth ground. Alternatively, employ a commercially available wrist strap device, which for your personal safety should be removed prior to applying power to the unit under test.

2. After removing an electrical assembly equipped with ESDs, place the assembly on a conductive surface, such as aluminum or copper foil, or conductive foam, to prevent electrostatic charge buildup in the vicinity of the assembly.

3. Use only a grounded-tip soldering iron to solder or desolder ESDs.

4. Use only an “anti-static” solder removal device. Some solder removal devices not classified as “anti-static” can generate electrical charges sufficient to damage ESDs.

5. Do not use Freon-propelled chemicals. When sprayed, these can generate electrical charges sufficient to damage ESDs.

6. Do not remove a replacement ESD from its protective packaging until immediately before installing it. Most replacement ESDs are packaged with all leads shorted together by conductive foam, aluminum foil, or a comparable conductive material.

7. Immediately before removing the protective material from the leads of a replacement ESD, touch the protective material to the chassis or circuit assembly into which the device will be installed.

8. Maintain continuous electrical contact between the ESD and the assembly into which it will be installed, until the ESD or assembly is completely plugged or soldered into the circuit.

9. Minimize bodily motions when handling unpackaged replacement ESDs. Normal motions, such as the brushing together of clothing fabric and lifting one’s foot from a carpeted floor, can generate static electricity sufficient to damage an ESD.