laptop 19v short circuit dell vostro 1400 motherboard ,need help in repair .

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the comon problem they say , the charger will shut off power once plugged to laptop , i dont have battery, its long gone ago , i use it for backup with adapter and vga port to external monitor(yes no screen lcd) in case my desktop needs fix . one thing for sure i could say the clr resistor - r010 beeps ,short at both sides , the checked all the coils , the 3 coils together gives all of them beeps short along with their respective capacitors . i dont have voltage ampere injection dc machine as in videos i have seen they see where its getting hot and they remove the short and replace components . i dont have hot air gun, only solder and multimeter ., please kindly go thorough the pics , if any section wanted to be more clear , please kindly mention , i will try more better pic in day time.
so all of you sure experienced with the looks of and shortcuts to solve this problem , please tell me what to check and what could be removed and trial methods.. people here are asking too much money for this. hope to learn good and solve if i could .. thank you all .

[mon2]

Share the silk screen markings on the board. Perhaps something like 'LA-****' onboard? This will help to locate a suitable schematic.

When you attach the power adapter, are you able to measure ~19v stable to ground on the board? Being a Dell, there is a 1-wire communication line that is used by the EC (onboard microcontroller) to gauge the power rating of power adapter. If this connection is absent or defective, the power adapter, by default, is deemed to be too weak to power and charge the battery.

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mon2 thank you for replying sir, silk screen markings ?? you mean to remove those sticky pads and take pics of them ? this is vostro dell 1400 mobo , there are schematic already available , i will attach its pdf now here. btw i dint check any voltage because , the moment i plug in , the adapter shuts down, the green light on it goes off. so i dint think of measuring voltage. the power port dc is like a needle goin into a hole , the back of power dc port is like 3 pins .

[mon2]

1) you should be resting now You can hit this tomorrow after eating some tasty masala dosa.

2) The needle like pin is actually the PS_ID pin. This tiny contact is the one that is used by the logic board and the local EC (microcontroller) to gauge the power rating of the adapter.

3) You will need to carefully measure the voltage to ground of this needle pin (after it is on the logic board). This voltage should be ~3v. Also check the main power rail for the ~19v.

4) A general suggestion is to remove all power -> meter in resistance mode -> test the resistance to ground of each inductor. If an inductor is with a low resistance then there may be a shorted part onboard and this is causing an excessive current draw and the local power regulator is shutting down.

Start with inductor @ FL5. This is the MAIN power rail. What is the resistance to ground of this power inductor? Meter in resistance mode. One meter lead on this 2 legged part (either side); other meter to ground (metal shield) is ok. Meter lead colors do not matter. NO POWER to the board in resistance mode checking. No battery either !!

We are checking if there is a short on the main power rail which can also lead to the same observation as reported.

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marked pics as much i know , dont know much deeper.

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not a problem i had my sleep , should i put the plug in this board now and check what it shows on board ? but it powers off tho !! ?? .. and about the inductor ?? you mean those cube like grey boxes ?? the 3 of them together looks like shorted , i tried them in diode mode in multimeter .yes i removed everything , its just a bare circuit mobo now. notihng is in it , no cpu ram cmos ..

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in resistance mode - those 3 grey cubes together near to cpu are showing only 4 , the rusted once near battery hows 12-14 , others are around 500-600s

[playit]

1) you should be resting now You can hit this tomorrow after eating some tasty masala dosa.

2) The needle like pin is actually the PS_ID pin. This tiny contact is the one that is used by the logic board and the local EC (microcontroller) to gauge the power rating of the adapter.

3) You will need to carefully measure the voltage to ground of this needle pin (after it is on the logic board). This voltage should be ~3v. Also check the main power rail for the ~19v.

4) A general suggestion is to remove all power -> meter in resistance mode -> test the resistance to ground of each inductor. If an inductor is with a low resistance then there may be a shorted part onboard and this is causing an excessive current draw and the local power regulator is shutting down.

Start with inductor @ FL5. This is the MAIN power rail. What is the resistance to ground of this power inductor? Meter in resistance mode. One meter lead on this 2 legged part (either side); other meter to ground (metal shield) is ok. Meter lead colors do not matter. NO POWER to the board in resistance mode checking. No battery either !!

We are checking if there is a short on the main power rail which can also lead to the same observation as reported.

can you please tell me the name according to our pics shared , the schematic is not matching much , i dont see that fl5 ??
there is coil inductor named e5r2 near the battery port - its resistance to ground at both ends are in 670s

[mon2]

See attached for the inductor locations that I can see from your pics.

Hunt for the battery charger IC with white silk screen of 'PU7'. The inductor for the main power rail will be nearby @ FL5. Share close up pics of the area.

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those yellow things you marked, i already took readings of them in diode mode and resistance modes -- in resistance mode - as said above" those 3 grey cubes together near to cpu are showing only 4 , the rusted one near above battery port hows 12-14 , the middle one near to the ram is 80 , all others are around 500-600s and the pics closer ones hope they are clear

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back side of battery port under pu2 is there . 0508073 82kje1L chip is there,above it pu2 is there. also this another pic i strip some sticky thing , hi found another version schematic of vostro 1400 may be its closer , please kinldy check it..

[mon2]

See attached. Can you confirm if this capacitor is truly burnt looking?

With no power to the board - meter in resistance mode (not diode) - measure the resistance across the tips of this capacitor. We are checking if this part is shorted or not.

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c117 the one shown in circle i believe doenst looked burnt , the resistance on tips across the capacitor in 2000 mode - 54 and 82 (reversed) , when both probes touching each other - its 2 . sorry for late reply , i left my computer on and slept ,good morning / evening

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hello ,for diy voltage injector -- is it possible to use something like this - LM317 DC Linear Regulator, DC-DC 4.5~40V Turn 1.2~37V, Step Down Power Module, Adjustable

and ampere controller along (to make it zero amps ) with some addons for it -- and use some 5v adaptor or 3.3v volt rail of my smps power supply as input and finally get 1v and zero amps for injecting voltage to find out short circuit component ? ..
for source input -- can we use 3.3 -4 volt 18550 battery ?( i have some of those ) and then adding ampere regulator to make it zero as 18650 have some amps 3000mah .. the real machine for voltage injector is expensive for me to buy here. so thought why not think about it of the final result it delivers and could make it diy if possible ..thank you . will make this a new post too , will be very handy in future if this is possible in low cost. thanks

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c117 the one shown in circle i believe doenst looked burnt , the resistance on tips across the capacitor in 2000 mode - 54 and 82 (reversed) , when both probes touching each other - its 2 . sorry for late reply , i left my computer on and slept ,good morning / evening

i rechecked the c117 the one you pointed out in circle its 160 and 80 in 200 resistnace mode.

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may be this schematic matches close enough , please take a look , its 1420 inspiron motherboard exact same like vostro 1400 motherboard that i have .

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these schematics are rev 0.1 , my board says its rev- a00 ,its confusing , the numbers many of them dont correlate with the board
mon2 sir , this 1420 elsa uma matches part numbers better than any other schematics above. please kindly watch it . thank you.

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mon2 i checked pl8 (rusted look inductor ) gives 14-15 in resistance mode -this says 1v vccp section might be bad ? it should be in 90 to 100s i saw in a video , and those pl 12 , pl13, pl 14 - three things near cpu is giving nil resistance as of ground. this section says vcc core is short.
from the schematic vcc core is isl6260c isl6208 runpwrok imvp vr on .
vccp is 1.05 run on -sn0508073

[mon2]

Wasting my life in attempting an A2337 repair for a local. Apple wants him to throw it away. Have it 50% working now.

Measure the resistance from the main power rail to the vcore inductors. Either side of inductor is ok. Testing if there is a high side mosfet leakage which will have nuked the cpu. However, is the cpu not removed from the socket?

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oh sorry to be disturbing you while repairing that bitten apple , hope you will be soon successful to 100% , yes sir the cpu is removed at first , i dint keep anything with it in first place, its only a bare board now .removed cmos too at first. hmm not sure how to measure from main power rail ,will try to figure out , oh mm is that means i should not keep ground ?
i kept ground probe at middle pin of jack dc which is 19 v , then red probe to those 3 inductors all of them showed 900s resistance /in reverse nothing shows up. there is a "220 82hs d" in front of those 3 inductors then cpu . may be its broken ?? its a diode i guess , schematic says its 220uf/2v pt_c7343d_h75 SANYO/2TPF220M7 -- ah its polymer capacitor