Use dc power supply to find short heated meathod?

[PeteS in CA]

Re: Use dc power supply to find short heated meathod?

If you want something more sensitive than your finger tip, try dabbing rubbing alcohol on components with a cotton swab and look for parts where the alcohol evaporates REALLY quickly. Freeze spray works, too, but that will condense water out of the room air, probably not good unless the PWA is conformal-coated.

[diif]

Re: Use dc power supply to find short heated meathod?

Please look at this https://www.ifixit.com/Teardown/Sams...Teardown/17357

Scroll down till u se image of the ic highlighted in different colours tells u each ic name

Ok, I'm on the page, I see the names, what am I looking for ?
Have you got a close up photo of your board now that the component has been removed?

[Stevie2001]

Re: Use dc power supply to find short heated meathod?

Please look at this https://www.ifixit.com/Teardown/Sams...Teardown/17357

Scroll down till u se image of the ic highlighted in different colours tells u each ic name

[diif]

Re: Use dc power supply to find short heated meathod?

I also Googled U492 galaxy tab t210 and it's the 6th/7th link. There is a translate link.

What trouble shooting brought you to inject 5V there ? Page 8-4 of the service manual has the troubleshooting steps for no power on.

[Stevie2001]

Re: Use dc power supply to find short heated meathod?

I found reference to it on the Russian page and also here http://forum.gsmhosting.com/vbb/f258...ounds-2119234/

I se interesting good find.
I wonder were i can find this part tge russian site i dont understand it.

I want to know why the audio ic heated up causing power issue.

[diif]

Re: Use dc power supply to find short heated meathod?

How do u know that ic is audio

I found reference to it on the Russian page and also here http://forum.gsmhosting.com/vbb/f258...ounds-2119234/

[Stevie2001]

Re: Use dc power supply to find short heated meathod?

U492 is the ic audio amp.
I can find one in Russia. http://originalspareparts.com.ua/parts/120/2/

How do u know that ic is audio.
I broke the ic of the board the caps stil beeping? Maybe i should add the new ic and se if it works or should i give it another amp test to se what else smokes?

This is the exact board i have
https://youtu.be/0luG-xUqByY

[diif]

Re: Use dc power supply to find short heated meathod?

U492 is the ic audio amp.
I can find one in Russia. http://originalspareparts.com.ua/parts/120/2/

[Stevie2001]

Re: Use dc power supply to find short heated meathod?

Super zoom to the blown part.
Its for galaxy tab 3 rev 5

4811
4011
9 joints to this chip
Wonder were i can get this from.

[Stevie2001]

Re: Use dc power supply to find short heated meathod?

Please check post 11 attachment is that the culprit caused no power.

Diff not sure what the marking was but can you tell me if that was the part causing the issue.

Really thank you for your generouse time.

[diif]

Re: Use dc power supply to find short heated meathod?

Ok lol i got sick of it and as i was holding it while the amps was on 4 i set it to 5 and the ic next to the caps smoked is that the culprit

If the magic smoke came out it's dead now. What are the markings on it ?

You can also measure for shorts with a meter in diode mode, put the red probe on ground and the black on the rail to check.

[budm]

Re: Use dc power supply to find short heated meathod?

The beeping mode of the meter does not mean you have shorted circuit, your meter may beep with resistance as high as 50 Ohms, try it with a bunch of low Ohms I.E. 10 Ohms, 47 Ohms resistor to see if the meter will beep or nor. Beeping mode is for testing to see if there is connection between point 'A' and point 'B'. Use Ohm mode to look for shorted circuit.

[Stevie2001]

Re: Use dc power supply to find short heated meathod?

Ok lol i got sick of it and as i was holding it while the amps was on 4 i set it to 5 and the ic next to the caps smoked is that the culprit

[Stevie2001]

Re: Use dc power supply to find short heated meathod?

You're aware there's a load of components on the other side of that pcb ? It needs removing from the chassis as it's possible something that side has shorted.

Here's the service manual if you don't have it already.

Yes its out of the casing and the board is out only am touching it both sides no heat i can hear the dc power supply fan turning on due to the current being set to 3.xxamps and low voltage drop

[diif]

Re: Use dc power supply to find short heated meathod?

You're aware there's a load of components on the other side of that pcb ? It needs removing from the chassis as it's possible something that side has shorted.

Here's the service manual if you don't have it already.

[Stevie2001]

Re: Use dc power supply to find short heated meathod?

Setted 3.52amp stil not heated components am i doing it wrong

[Stevie2001]

Re: Use dc power supply to find short heated meathod?

There's a decimal point in there. It's 1.36A. You have the current limited, I usually inject 3A to find the short/hot component.
You should disconnect the battery before testing/injecting voltages.
Why not remove the capacitor and see if the short goes away?

Thanks for the reply i removed the caps before and they was fine because it didn't beep i connected the wire of multimeter to the pins on board were the caps was and it beeps so am trying to figure where the short is coming from i tried freeze spray but no sighn of heat.

I will try set more amps i just hope am doing it right when i connect the dc power supply pin to the shorted part the current goes to 136 and board dont heat

[diif]

Re: Use dc power supply to find short heated meathod?

There's a decimal point in there. It's 1.36A. You have the current limited, I usually inject 3A to find the short/hot component.
You should disconnect the battery before testing/injecting voltages.
Why not remove the capacitor and see if the short goes away?

[Stevie2001]

Re: Use dc power supply to find short heated meathod?

I set to 5v voltage and touched the red pin to the short cap.
I say its shorted because it beeps both sides also if i touch gnd and any side of the cap it beeps also when i connect the dc power supply to the cap voltage drops and current goes upto 136.

The first image showing which two caps.
The second image showing me connecting dc power supply drawing current.

00.6 Ohm.
I took the caps out before and the both legs points on the board beeps. Tested the cap if it beeps while it was removed and it didnt

[budm]

Re: Use dc power supply to find short heated meathod?

160 just random numbers

160 Amps?
Power supply is only rated at 5A.
https://alexnld.com/product/qw-ms305...tandard-white/
If you use Ohm meter to check the resistance of the shorts, how many Ohms do you get?