| I wouldn't be a decent technician if I didn't list the power wheel somewhere in this blog. |
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( 2.7 / 35 )| Now That you know how to use a multimeter lets figure out how to read resistance on a resistor. |
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( 2.7 / 21 )Lets Talk about multimeters. There will come a time when you will need to to check the voltages on the board or worse yet the voltage come out of the wall outlet. You also use your voltmeter to check continuity. If a piece of wire has no breaks the meter beeps. If it does not there is no continuity. I am going to go into all of this below but here are the basic specs of your multimeter. Don't buy any baby stuff. Your multimeter needs to be able to handle atleast 120 volts and 20 to 30 amps. Standing copiers do about 10 amps and high capacity copiers start at about 20 amps. If your wall outlet isn't even meeting the specs of your copier then thats a problem. If you multimeter cann't handle this get a new multimeter. It sounds funny but its a point of safety.
A multimeter is used to make various electrical measurements, such as AC and DC voltage, AC and DC current, and resistance. It is called a multimeter because it combines the functions of a voltmeter, ammeter, and ohmmeter. Multimeters may also have other functions, such as diode and continuity tests.
Lets start with testing for continuity. This test should be done when current is NOT present. Always unplug the device or turn off the main circuit breaker before attempting a continuity test. Always test your test equipment for proper operation before use.
A continuity test is done to determine whether a circuit is open or closed. For example, a wall switch is closed when it is turned to the "on" position and it is open when it is turned off. An open circuit cannot conduct electricity. A closed circuit has continuity.
To test the continuity of a circuit requires the use of a multimeter (also called a multitester) or a continuity tester (a simple device that lights up to indicate continuity).
Set the multimeter to the ohm setting. The symbol for ohm is , the Greek letter omega. If there is more than one ohm setting, choose X1. An analog meter uses a needle to indicate the measured value. A digital meter performs the same test functions as an analog meter, with the key difference being that a digital meter provides a numeric reading instead of using a needle.
Note that while the probes are not touching anything, the multimeter will indicate a reading of infinity. A reading of infinity means that the circuit is open. When you touch the two probes together, the reading changes to zero. A reading of zero indicates that the circuit is closed or complete. A complete circuit is one that can conduct electricity; an open circuit cannot.
When measuring voltage, measure voltage with power applied to the circuit. When making a voltage measurement with a multimeter, the first step is to switch the multimeter to the highest voltage ranges. It is best to select a range higher than the expected voltage so that there is no chance of the meter being overloaded and damaged. In addition to this check that the test leads are plugged into the correct sockets. Many multimeters have different sockets for different types of measurement so it is worth checking the correct ones have been chosen before making the measurement. Usually a meter will be provided with two leads, one black, and the other red. The black one is normally taken as the negative one. It is connected to the negative or "common" socket on the meter. The red one is connected to the positive socket.
Now Lets worry about measuring current. Turn the meter on. Insert the probes into the correct connections - in many meters there are a number of different connections for the probes. Often one labelled common into which the black probe is normally placed. The other probe should be entered into the correct socket for the current measurement to be made. Sometimes there is a special connection for current measurements, and sometimes a separate one for either low or high current measurements. Select the correct one for the current measurement to be made. Set main selector switch on the meter switch to the correct measurement type, (i.e. current) and range for the measurement to be made. When selecting the range, ensure that the maximum range is above the expected reading anticipated. The range on the DMM can then be reduced as necessary. However by selecting a range that is too high, it prevents the meter being overloaded. When the measuring the current, optimise the range for the best reading. If possible enable all the leading digits to not read zero, and in this way the greatest number of significant digits can be read. Once the reading is complete, it is a wise precaution to place the probes into the voltage measurement sockets and turn the range to maximum voltage. In this way if the meter is accidentally connected without thought for the range used, there is little chance of damage to the meter. This may not be true if it left set for a current reading, and the meter is accidentally connected across a high voltage point
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| Its always good to be self sufficient and with network cables this is doubly so. If you are a technician and you are doing networking its a good idea to make network cables. With cables costing as much as $30 a pop, its cheaper to buy a spool of cable and the end connectors as well as the crimper and go to town. Management can always charge for the service and you, my dear tech look absolutely brilliant. One thing to keep in mind when making network cables is you don't have to strip the actual wires inside. Most instructions say this but if you are someone like me who doesn't know their own strength you can actually rip the wire inside the cable and not know it. Your best bet when making cables is to strip the of the outer cover, seperate out the cables, organize them by apropriate color order, cut them with the crimping tool then apply the end connect and crimp. Remember your instructions even the ones here say strip. Stripping isn't neccessary. When you crimp, the end connect will cut right into the wires and make the connection. | ||||||||||||||||||||||||||||||||||||||||||||
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( 2.5 / 39 )Now lets talk about assembling copiers. Copiers are the easiest things in the world to assemble if you have a good bit of mechanical aptitude, like to solve jigsaw puzzles and read the instructions. Remember before you do anything talk to your manager find out what copier you need to assemble and what options are included... For example you might need to setup a copier that does 30 page a minute with a document feeder and a finisher with fax card installed as well as a print/scan card. So before you do anything get the details on what you are going to be assembling. There is usually an assembly guide in the package but on the off-chance there isn't then you can usually download one from the manufacturers service site or in some cases, you find this in the manual. Use the assembly guide to walk you through the process, experience and inexperienced tech alike should use the guide. That said and done your next step is to assemble all the components, the copier and all the optional parts. Now that you have everything assembled, its time to write down the part name, part description and serial number. This will spare you a lot of headaches later on. After doing that, I usually take a quick bathroom break to wash my hands and clean up a bit. Depending on the shop, you could get very dirty and some copiers are colored cream to white so dirty hands might actually work against you. That done... Your next step is to unpack. I usually take apart the boxes containing the copier frame and the box that contains the stand. At this point, I usually need the help of a second tech to set the copier on its stand. After which, I bolt down the copier frame to the stand if that is possible. I then install the document feeder. At this point, I remove all tape and test the copier. Why? Why not just keep going...??? You need to verify that the main body works before you start adding stuff to it. Attachments such as finishers and document feeders and such are nice but if you assemble everything all at once without testing the main frame then when you test at the end you really won't know where the problem is if there is a problem. Or it may take you quite a bit longer to find it... After verifying that the trays work, the copier can do all its functions, I then add all the options that are specified. Keep in mind, each option has an assembly guide that you need to walk through. I test again and verify that all is ok. If not then I troubleshoot until it is ok. Once all is well, then I update the firmware to the latest and greatest, set the dates, add in any settings that the customer requested, give the copier a good cleaning and then send my manager an email. Two things to note 1) a copier can ship with a defective drum or board or other part and 2) there are times when copier does not assemble as expected. Don't depend on these points because these failures are rare and far between. Test and double test and triple test before you fall back to these points. The issue may not be the copier but your lack of experience or experience assembling the copier the wrong way.
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( 2.9 / 71 )
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