What equipment??

[newtothis]

Ok it is getting very tiring pulling tonnes of SMD components from boards in an attempt to find a short on the board... So..

What is the best method of finding shorts?
What equipment is needed?
Suggestions of best make/models of equipment?

Cheers guys

[stj]

Re: What equipment??

a low ohms meter.
you may get away with using an esr meter.

[newtothis]

Re: What equipment??

How do you find a short with an ESR meter?

This card I have had in today has a short somewhere down one of the 12v rails.... Of course on my meter it is showing 0 ohms across the pads of many components... Would this not also be the case with an ESR?

I have read up about people using variable PSU's and pushing a small current through the circuit then using a sensitive meter to track the path of the current.

Basically I am looking for the quickest way of finding them

[stj]

Re: What equipment??

esr meters can often show resistance with a higher resolution.
my meter for example can show xx.x ohms
an esr meter can show xx.xx
10 times more detail.

the resistance of the solder and copper tracks is very small, but it's still there, so with a good enough meter the short will show a lower resistance as you get closer to it.

there used to be circuits for this using a speaker that generated a tone that rose in pitch as you got close.
maybe you can find one.

[newtothis]

Re: What equipment??

Can you recommend a decent ESR meter for the job then? I only have this crappy homebuilt thing which is useless TBH

Are the Atlas readers any good?

[stj]

Re: What equipment??

atlas are very overpriced.

either get a cheap ebay job like this:
http://www.ebay.co.uk/itm/181573126240

or talk to Behemot about the quality Russian one he sells.

as for finding shorts though, go look on schematics sites for a low-ohms tracer.

[newtothis]

Re: What equipment??

LOL I am crap at reading diagrams nevermind building a circuit! Remember my name stj! lol

[SteveNielsen]

Re: What equipment??

Even a cheap Chinese knock-off of the Kubbeler AVR tester can measure resistance down to hundredths of ohms. Those can be had for around $25.

[newtothis]

Re: What equipment??

Takes too long to get things in from abroad. Also i had a cheap ass thing from HK before and it died within a week.

Price isn't an issue to me

[stj]

Re: What equipment??

found this - it looks simple.

[newtothis]

Re: What equipment??

Simple as it may be I can't build circuits so I will need to buy one

[SteveNielsen]

Re: What equipment??

I don't think you should limit yourself like that, you CAN build circuits if you just start doing it and you've got to start somewhere.

[newtothis]

Re: What equipment??

It is not something i intend on getting into so no point. On average I spend 30 minutes per repair on Video Cards, I make an average of around £100 profit per card, I get through around 10 reballs per week so make around £900 after expenses. I started seeing a higher amount of cards with dead shorts lately which is something I need to be able to address properly rather than pulling LOTS of smd components to find them. Taking the time to learn how to build circuits + buying in the stuff needed just isn't worth my time.

[stj]

Re: What equipment??

i pm'd someone - wait for Behemot.

[Behemot]

Re: What equipment??

Oh yeah here I come I can supply the newest ESR Micro v4.0si, or if you don't need the relay protection (for charged capacitors) also the older v4.0s for cheaper. As my stock is sodl out and Mikhail is on vacation now, it does not matter which you choose, I'll need to order all of them

It can measure 0.01-200 ohm and capacitance 0.01-65535 uF.

[mmartell]

Re: What equipment??

Is the idea here is to test across components or pick a ground location and move the other probe around ?

[rievax_60]

Re: What equipment??

I have been having good success at finding shorted Multi-layered Chip Capacitors using about 0.5A of bias current and using a multi-meter with at least 10uV resolution by measuring the voltage drop on the ground plane. The readings increase as I get closer to the shorted MLCC.
Some example photos on this page,
https://www.badcaps.net/forum/showth...164#post423164

[Behemot]

Re: What equipment??

How exactly does it work? And 10 uV is really too low…

[stj]

Re: What equipment??

he is tracking the volt-drop.

[SteveNielsen]

Re: What equipment??

The meter is set to 10uV resolution to measure small changes in voltage, that's not the voltage he's applying to the ckt.