[bushwhacker]

Hello guys

I cannot understand what tutorial video is talking about the mutlimeter, so i need your helps.


Can you tell me what mode selection is used, and what should i use for the computer checking.

Such as, checking for capacitors, LED, resistors, and so forth.

Thank you for your time.

Edited: Sorry, forgot the picture.

[alan2273]

To test things on your computer for voltages you need to select DC voltage, which is the V with broken lines and a solid line above it.
for resistance you need to select the Omega sign.
Do not try to test capacitors as they can hold several thousand volts which will fry your tester.
To test for the current being drawn you need to set it up in a serial loop and use the A with the broken line and solid line above it.
The A with the wavy sign above it is for testing alternating currant IE mains voltage.

This might be of some help to you.
http://articles.techrepublic.com.com...5-1053275.html

[bushwhacker]

Then, How can i test it, so i can verify if the capacitor is bad or not ?

[wektech]

Here is an interesting article on test capacitors using a multimeter http://www.repairfaq.org/REPAIR/F_ca...ml#CAPTEST_004. Keep in mind that testing capacitors generally require that you remove the cap from the circuit, which is not really practicle.

[bushwhacker]

Not bad finding.

Anything about general motherboard troubleshooting using the multimeter?

I only found something related to PSU's rails.
http://www.driverheaven.net/guides/testingPSU/

[alan2273]

Taken from Tech Republic.

without some serious test equipment, you cannot test a cap in circuit. There are no purely capactive circuits, so testing while on the board will render wrong reading to the great untrained. Parallel resistance, series inductance, diodes, will all change your meter reading, add to the mix, the hazards of probing around a CMOS environment with a voltage source (ohm meter probes) is a disaster in training.

Your best way to check for a bad cap is electrolytic oozing from the can, a BULGING cap, not just a can with a slight hump, but one that looks pregnant, and of course, when you have capacitor guts all over the inside of the case. Even if you do faind a bad cap, now you are going to have to replace it, I hope you have a good de-soldering station, boards are multi-layer

[bushwhacker]

Ok you mean i will damages my motherboard if i do some multimeter test on some capacitors?

[Daveskater]

I think what he means is that you can damage your mobo if you test the capacitor whilst it's on the board.

You can spot faulty capacitors be looking at them, unless you think that you need to check them with a meter.

This is what a leaking one would look like:


And this shows you a bulging one:

[Dano2k0]

Not only can it be one of the above, in some RARE cases they can look reasonably normal and fail, though they tend to show some signs. Ive seen a good few cases of exploded caps on boards aswell.

The only real way to test a cap to its value is indeed to remove it from the board and your multimeter would have to be capable of cap testing.

[bushwhacker]

Well. I have this old board lol.. It would be nice if i resurrect it.

One capacitor was full bulged out, so i grounded the black probe( Motherboard brackets, metal grounds ) and test the few capacitors, on the broken line V 20, few of them works just fine, but the bulged capacitor, i got nothing.

So i guess i didn't damage my board after all ?

[Albert Lionheart]

Probably not, but from a commercial standpoint there is no sense in trying to repair a board when you can get a half decent one from gigabyte for as little as £30/$60. That is equivalent to about 15 mins of an engineers time!
Fat caps is the biggest single killer of m/boards - I see them all the time especially on cheap boards like Jetway.

Originally Posted by Daveskater

I think what he means is that you can damage your mobo if you test the capacitor whilst it's on the board.

You can spot faulty capacitors be looking at them, unless you think that you need to check them with a meter.

This is what a leaking one would look like:


And this shows you a bulging one:

Great pictures Dave - a great help as most people seem incapable of seeing a fat cap.
cheers

[Daveskater]

Originally Posted by Albert Lionheart

Great pictures Dave - a great help as most people seem incapable of seeing a fat cap.
cheers

No problem, mate

Pictures never hurt in situations like this and it only takes a few seconds to google for some

[bushwhacker]

All right thanks guys, i'll try to replace a capacitor and give it a try

Thanks for handy lessons guys.