I injected around 1-2v at the +PWR_SRC and observed the component that heated up. Removed the component from the board and verified that it was the culprit.
I have been finding shorted capacitors by measuring the voltage at the capacitors's ground end with the millivolt range. I try to get the current up to 0.5A but dont exceed 1v incase the problem is really a shorted High Side MOSFET.
The readings gradually increase as you get closer to the shorted capacitor. There usually is a very small voltage difference between a nearby solder fillet and the top of the end cap at the shorted capacitor.
i really try to understand i swear.
PWR_SRC usually you find only in dell right? and thats 10->19V
so injecting 1v - 0.5a where?
off i`m sorry if i bother you
Its also possible to narrow down the location of the short by removing those solder blobs that you see joining breaks in rail tracks. I use a large tip and desolder braid. Adding some leaded solder and flux first, makes it easier to clear all the solder from the very narrow gap.
i got m5040 and xps 1535 with no power, can i use this method to find the problem?
you can use this method only if there is a short on the 19v rail (+DCBATOUT or +PWR_SRC has a resistance of a few ohms or less with respect to ground).
you can use this method only if there is a short on the 19v rail (+DCBATOUT or +PWR_SRC has a resistance of a few ohms or less with respect to ground).
off i`ll try one more time.
i don`t wanna upset anyone
Voltage=
Location=
side=
like you said rievax_60
Voltage=??
Location=PL6
each side(no metter)
i don`t think its very hard to explain when you test something how you do it
i just wanna learn.
for 1 what happen when i put 1V with 0.5a on cap and putt the dmm on the other side?
where did he use that 1V? on a 19V rail? pfff No!
First you should do a resistance reading between one end of PL6 and ground to see if there really is a short.
If there is, connect The + of the bench supply to one end of PL6 and the - to ground print.
Dont apply more than 1v.
I hope you understand the basics like how voltage, current and resistance interact.
Have you learnt Ohm's laws? You need to understand why you are being asked to do something and think for yourself.
First you should do a resistance reading between one end of PL6 and ground to see if there really is a short.
If there is, connect The + of the bench supply to one end of PL6 and the - to ground print.
Dont apply more than 1v.
usually there must be a good value and a bad value when there is a short right?
i mean or on the bat side or on the dc side.
what value its considered a short?
because when you try to see it you need to take it from the top, like take a bat mosfet and disconnect that side right?
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