+1.05vtt_pwr cpu and pch power rail short to ground

[samanthban]

DELL N5040 DV 15 CP UMA MB 10263-1

This laptop came as no power ,first check 19v rail was short to ground and removed easily .cap was pc 4813

then checked PL4902 short to ground as shown in the picture .







I failed many time when injecting voltage to this rail . and i have checked PC4901,PC4910,PT4902,PT4901 all are ok.

please give an advice any expertise regarding this matter.

[fddizon]

Re: +1.05vtt_pwr cpu and pch power rail short to ground

hi,

im no expert but you can try checking +1.05V_CPU rail
C4901 and dual channel FET PQ4901 are few of the candidates

[fddizon]

Re: +1.05vtt_pwr cpu and pch power rail short to ground

see this transfer of name inside the yellow box

[samanthban]

Re: +1.05vtt_pwr cpu and pch power rail short to ground

hi,

im no expert but you can try checking +1.05V_CPU rail
C4901 and dual channel FET PQ4901 are few of the candidates

Thanks for your idea will check for that as you said .this power rail is so big its goes to many places any tricks that can find the faulty one.

[samanthban]

Re: +1.05vtt_pwr cpu and pch power rail short to ground

pq 4901 is ok and c4901 place is empty

[jasko_jacker]

Re: +1.05vtt_pwr cpu and pch power rail short to ground

if I understand well , you have removed the coil PL4902 and the short is on the right side, on +1.05VTT_PWR -> +1.05v_pch ?
If you can not isolate this branch (+1.05v_pch), one method is to desolder a lot of components,I don't remove the component, but I positioning it vertically on one of his pad (when is possible).
C2601 & C2602 -> VCCCORE
C2613 ->
C2704 & C2705 & C2708 & C2710
C2728 & C2729 & C2730
C2725
PC4901 -> not in place
PT4902 ->
L2702 & L2703
probably there is a short inside the pch
Or remove
Pl4902 and PR4912 and inject a 1.05 V 1.5 A and try to find a cold component

[dellxps15]

Re: +1.05vtt_pwr cpu and pch power rail short to ground

cant read well, but remove pg4908 jump and pr4903 and see if still short. if yes short is on some caps (pc4901 ... etc etc) , otherwise is in cpu.

edit: be sure what cpu is in it. some cpu like series 3 intel i7 3710QM will show 001 or short on coil, but it is completely normal to have very low value....

[samanthban]

Re: +1.05vtt_pwr cpu and pch power rail short to ground

if I understand well , you have removed the coil PL4902 and the short is on the right side, on +1.05VTT_PWR -> +1.05v_pch ?
If you can not isolate this branch (+1.05v_pch), one method is to desolder a lot of components,I don't remove the component, but I positioning it vertically on one of his pad (when is possible).
C2601 & C2602 -> VCCCORE
C2613 ->
C2704 & C2705 & C2708 & C2710
C2728 & C2729 & C2730
C2725
PC4901 -> not in place
PT4902 ->
L2702 & L2703
probably there is a short inside the pch
Or remove
Pl4902 and PR4912 and inject a 1.05 V 1.5 A and try to find a cold component

if I understand well , you have removed the coil PL4902 and the short is on the right side, on +1.05VTT_PWR -> +1.05v_pch ? yes, it goes to pch and cpu

Thanks for giving me a direction try it and let you know

[samanthban]

Re: +1.05vtt_pwr cpu and pch power rail short to ground

cant read well, but remove pg4908 jump and pr4903 and see if still short. if yes short is on some caps (pc4901 ... etc etc) , otherwise is in cpu.

edit: be sure what cpu is in it. some cpu like series 3 intel i7 3710QM will show 001 or short on coil, but it is completely normal to have very low value....

Thanks for helping will try and post here

[samanthban]

Re: +1.05vtt_pwr cpu and pch power rail short to ground

edit: be sure what cpu is in it. some cpu like series 3 intel i7 3710QM will show 001 or short on coil, but it is completely normal to have very low value....

All day searched for faulty component but above sentence save me ..Thanks hundred times actually its normal

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