DELL Latitude E6400 Schematic Diagram

[Hardiansyah]

Re: DELL Latitude E6400 Schematic Diagram

anyone can help me, I have dell e6400, but that is not power, or totally died. I dont know how to check the crack component

[rabsonnjala]

DELL Latitude E6400 Schematic Diagram

Dell latitude E6400 schematic

[mehmood muhaish]

Re: DELL Latitude E6400 Schematic Diagram

i have problem with keyboaed faliure e6400 atg,plz help

[dj_ricoh]

Re: DELL Latitude E6400 Schematic Diagram

ahhh i left the mobo at work
i will start a new post so we don`t highjack it, tomorrow

[rievax_60]

Re: DELL Latitude E6400 Schematic Diagram

I dont know for certain, say 1K for now. What reading do you get?

[dj_ricoh]

Re: DELL Latitude E6400 Schematic Diagram

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?

[rievax_60]

Re: DELL Latitude E6400 Schematic Diagram

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.

[rievax_60]

Re: DELL Latitude E6400 Schematic Diagram

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.

[dj_ricoh]

Re: DELL Latitude E6400 Schematic Diagram

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!

[rievax_60]

Re: DELL Latitude E6400 Schematic Diagram

Why do you think there is a short?

[rievax_60]

Re: DELL Latitude E6400 Schematic Diagram

On the B+ rail. On page 43, either end of PL6 will do.

[dj_ricoh]

Re: DELL Latitude E6400 Schematic Diagram

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).

sry to bother you

like this?

or you supply the 19V from dcin

[whaldsz]

Re: DELL Latitude E6400 Schematic Diagram

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).

[rievax_60]

Re: DELL Latitude E6400 Schematic Diagram

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.

[rievax_60]

Re: DELL Latitude E6400 Schematic Diagram

The short is usually on the VBAT+ rail. Its the rail that normally has battery voltage or adapter 19v on it and feeds most of the Buck regulators.

[dj_ricoh]

Re: DELL Latitude E6400 Schematic Diagram

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

[rievax_60]

Re: DELL Latitude E6400 Schematic Diagram

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.

[dj_ricoh]

Re: DELL Latitude E6400 Schematic Diagram

i got m5040 and xps 1535 with no power, can i use this method to find the problem?

[dj_ricoh]

Re: DELL Latitude E6400 Schematic Diagram

0.5 A or 1?

[whaldsz]

Re: DELL Latitude E6400 Schematic Diagram

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.