Test components on the motherboard

r,

Is it possible (using a multimeter) to test the components on a laptop motherboard? No! Check eBay for a replacement.

fuses are about the limit, assuming they can be recognised or marked as fuses

On Tue, 12 Jul 2011 13:51:41 +0200, "Allen" put finger to keyboard and composed:

Yes. Which laptop do you have?

- Franc Zabkar

main failure on a motherboard is the capacitors leaking you need an esr meter to test them a multimeter cannot do that

you can get esr meter schematics free and commercials here :

regards,

I think your heart's in the right place. What you said isn't wrong. BUT In the spirit of educating the OP, it might lead to a less efficient and more expensive solution.

Assuming that the OP has the expected senses for a primate, "leaking" caps can be diagnosed with only one good eyeball. Bad caps can also bulge. That too can be diagnosed by eye. Bad caps with high ESR can get hot. That can be diagnosed with a finger...being careful not to burn yourself.

I did a bunch of experiments with a TDR system measuring ESR. I had mixed results in-circuit. There's just too much other stuff affecting the reading...like other caps in parallel. Getting the caps out without hurting them or the board is a problem. Anybody with the equipment to do it safely would not have asked the question in the first place.

An easier test is to put an oscilloscope on the power bus and look for spikes. So, I'd recommend a cheap used oscilloscope LONG BEFORE recommending an ESR tester.

IN-circuit testing of any component is iffy unless you know the circuit. NOT the typical circuit...the EXACT circuit. That info is typically unavailable. I can't count the times I chased my tail on a problem because I assumed that the designer had done something reasonable.

I'll try to be respectful of the OP, but the way the question was asked suggests that he hasn't much chance of fixing the system. Given detailed symptoms, he might be led thru some simple diagnostic procedures. He might get lucky. Once you get past the broken solder connections on the power supply socket and blown fuses and shorted diodes, there ain't much to be done by the amateur with no (appropriate) test equipment. Just accessing circuit nodes on both sides of a board that has connections everywhere and heat sinks bolted to the infrastructure is problematic.

Even if you find the bad part there's the problem of acquiring one and replacing it without breaking something else.

Given the complexity and throw-away nature of today's products, I've come to the conclusion that it would take less time and effort to get a part-time job slinging burgers and use the extra income to buy a new device.

I don't care for the advice to buy a new board on EBAY. The most likely reason for ANY device to be sold is that it no longer works properly. That goes triple for an anonymous market like EBAY. Sure, there's lots of good stuff sold there...but the stuff that's guaranteed good isn't gonna be cheap. The rest is a crap shoot.

"Franc Zabkar" ha scritto nel messaggio news: snipped-for-privacy@4ax.com...

HP Compaq NC6000

Regards

I think the practical limits are fuses, MOSFETs (lots fail with the gate shorting to the channel), and maybe solder joints at connectors, but with the latter it's probably better to simply resolder them. As Kripton said, testing capacitors requires an ESR meter, but I think with motherboards the capacitors usually have to be removed because they're usually in parallel with other capacitors. Also laptops tend to be made with high quality capacitors, which fail a lot, lot less often than the junk capacitors found on many desktop motherboards.

Try

hello on my web site I have collected a lot of schematics of esr meters (and other testers) most of them cost nothing using scopes as you describe or using very easy to find and cheap components to adapt to a multimeter take a look at the method described there I also give links to commercial esr meters, for those who dont want to make it themselves...

best regards,

You're being naive. One of the characteristics of a good educator that is lacking in industry and almost non-existent here is EMPATHY.

You must LISTEN to, INTERPRET the question and provide an answer that the questioner can understand. Goes without saying that you need to be good at it. Just because YOU can do something easily is no indication that the answer is appropriate in the context of the OP.

There's an exception for everything, but typically, the person who asks, "can I debug my laptop with a multimeter?" with zero specificity as to the symptom is unlikely to have the skills and equipment required to construct, debug and competently apply a DIY ESR tester...then execute the repair.

Stated another way, those skills would have been used to debug the laptop and to formulate a question that could be answered.

People come here in the hope that they can do complex things without the skills/background to do so. Sometimes, the best you can do for them is to say, "sorry Charlie, you ain't got the skills to do this." Provide very detailed symptom info and perhaps we can help.

Guessing the symptom, then guessing the cause is just a shot in the dark. Sending them off to buy an ESR tester is irresponsible.

I've fixed a few laptops in my day and I've NEVER had a bad electrolytic inside. In the power brick, yes. Inside the laptop, no.

On Tue, 12 Jul 2011 17:29:48 +0200, "Allen" put finger to keyboard and composed:

- Franc Zabkar

lol. Must remember that. Call it burgernomics.

In fact there's someone here that's ahead of the game and has got the slinging burger operation going!

Who, "Meat Slab"?