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Multimeter question

Does anybody know how to setup/use a multimeter to check iphone parts like dock flex connector, microphone, headphone jack, etc. It would be very usefull since the only way to check for funcionality of these parts is trying with a newone and we can make a mistake.

Thank you and sorry for my basic english.

Macpatagon

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Hi,

there are three tests modes on the multimeter you should be carefull with.

The first one is the resistor, second the diode and third the circuit test. The multimeter will send out a constant voltage of 9V, if it works with a 9V block battery, and shows in these test modes the value of the resistor, that the diode works or that you have a closed circuit or not.

As there are many parts as ICs and transistors on the logic board using a lower operating voltage than 9V, you can easily fry one of these parts in worst case.

So if you are using a multimeter in one of these test modes, be sure to disconnect the part to be measured them from the logic board. In worst case you only fried this part and not the whole logic board.

How to setup/use the multimeter to test the parts you mentioned is a little longer story.

First you will need appropriate cables and clips/tips. Then you will need test setups for the part to be tested. A.e. you will need a cut off headphone plug with blank cable ends to hook a test clip to. For the other end of the headphone jack a very fine tip (like a needle), or a connector wit cables to hook another clip to.....a.s.o.

To make a long story short, if you don't want to repair iPhones and iPod professionally i would stay with changing the part and try if it works. Because its easier and faster.

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Hi Crisb, thank you for your time. You arr right, changing the part and try if it works its easier and faster...and less dangerorus!

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Yes for some things such as testing if the cable is good between the head phone jack and the other end of the cable that attaches to the motherboard. The cable will need to be disconnected from the motherboard to test that. The test is is called a continuity test. Most multimeters/mutitesters have this function. This kind of test is good for testing switches, such as the on/off switch, the cable will need to be unplugged from the motherboard. This test can also be used on cables from one end to the their end result, such as the head phone jack, again the cable will need unplugged from the motherboard. CAUTION: You do not want to run this test with a multitester across an IC you can harm them. Electricity follows the path of least resistance, therefore electricity will only flow between the path of the multimeter's test probes.

NOTE: You can actually make your own 3 volt continuity tester with a LED that shouldn't bother an IC. Instructions for doing that are here: http://www.instructables.com/id/Continui... For use as a tester for small things, such as iPone parts, I would modify the design in the instructable to do away with the big clip and use a probe tip on the end of the wire. I would also file down the tips of both "probes" to a fine point to ensure you are only touching and testing what you want to.

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So can it be done? Dou you know how? Thank you

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Just reading crisb's explanation confused me... I think it'd be helpful to others if you re-answered this question in plain and simple english....

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Do a google on continuity test. You will want to run a continuity test from the cables pins to the other end. The cables will need removed from the board so you can access their contacts. You will need to take a know good cable to find out what pins on the cable correlate to the other end. Draw pictures and write these down what you find. You will be making your own guides based on the results of testing good cables so you can test unknown cables. Here is a pin out the dock connector for some of the devices: http://pinouts.ru/Devices/ipod_pinout.sh... . You should be able to find the other pin outs with some searching. Good Luck!

CAUTION: What Chrisb says is correct about ICs, you do not want to run a continuity test across any IC you can kill it. The continuity test is good for testing head phone jack to the end of the cable and charging dock points to end of cable. Checking the wire for internal breaks. Good Luck!

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