HP G62 +5VPCU and VIN shorted

[sonunigam]

Hello All members,
I'm in a very critical situation that I'm repairing a HP G62 Which was dead and no light in Power Jack. I checked the voltages on Battery Connector, It shows that 4.8 Volts on +Positive. I Looked closely that KB3926QF D2 is short so i changed the IC. but now when i checked the +5VPCU and VIN the motherboard showing short. I removed the KB3926QF D2 but still same. I remove Processor but still same. I almost one by one remove and checked all IC's and FET's but it still shows short. Plz anyone can help that which is the thing is Shorted. I'm very upset for that. . . . .
I'll Appreciate if anyone can help me out. . .
Thanks to all

[spidey]

Re: HP G62 +5VPCU and VIN shorted

Hello All members,
I'm in a very critical situation that I'm repairing a HP G62 Which was dead and no light in Power Jack. I checked the voltages on Battery Connector, It shows that 4.8 Volts on +Positive. I Looked closely that KB3926QF D2 is short so i changed the IC. but now when i checked the +5VPCU and VIN the motherboard showing short. I removed the KB3926QF D2 but still same. I remove Processor but still same. I almost one by one remove and checked all IC's and FET's but it still shows short. Plz anyone can help that which is the thing is Shorted. I'm very upset for that. . . . .
I'll Appreciate if anyone can help me out. . .
Thanks to all

what do you mean "KB3926QF D2 is short ", Did you compare with schematic, do you have standby voltages such as 3.3v and 5v, did you check resistance of coils to ground ? did you check protection circuit and charging circuit ? ...

[sonunigam]

Re: HP G62 +5VPCU and VIN shorted

Hi Spidey,
first of all, i checked PC116 which is for +3VPCU was short, When i remove KB3926QF the shortage was gone. Now there're no Standby Voltages nor 3.3V neither 5V. I've checked PL4 with GND and resistence shows 37.3 Ohm. and PL2 shows 13.0 Ohm. I've checked Charging IC PU6 ISL6251A is ok. Where is the Protection Circuit? Will you plz tell me? I'm gonna uploading the Schematic Diagram so plz guide me to get rid off shortage. . .
By the way would you like to tell me that what is the meaning of +3VPCU or +5VPCU Please?
Thanks a lot

[bowor]

Re: HP G62 +5VPCU and VIN shorted

hi sonunigam, I can be the same case with your voltage is +5 vpcu short. usually are in need voltage is 5v power ic vCore (isl6262) it likes short, usb driver. try to check it!

[sonunigam]

Re: HP G62 +5VPCU and VIN shorted

Hi Bowor,
I'll check PU1, by the way thanks for your reply. . . .

[Francisco.s]

Re: HP G62 +5VPCU and VIN shorted

When i remove KB3926QF the shortage was gone. Now there're no Standby Voltages nor 3.3v

If you remove KB3926QF, then, S5_ON signal is removed also, so, some voltages needed in S5 state are not there.
Put a new embedded controller, and check voltage on power button and in pin 8 of 1M byte SPI EC ROM. (u13)
Before that check PU5 and its main output pins. (if it is correctly powered)
In this particular case, +3VPCU= +3VALW

[spidey]

Re: HP G62 +5VPCU and VIN shorted

+3VPCU AND +5VPCU are your standby voltages, it is normal that you dont have any standby voltages after you removed EC. Ec gives on/off signal to standby circuit. Be carefull when you replace KB3926QF xx with a new one, you have to solder correct version of this chip, like KB3926QF C0, KB3926QF D1.
it should be the same with the one desoldered. if charging is ok, probably protection circuit is ok. But after changing EC, i would also change rt8206b and check mosfets and caps around.

[sonunigam]

Re: HP G62 +5VPCU and VIN shorted

Hi all,
Hey Bowor, I've checked ISL6262, it is ok. not shorty, I'm very upset that how to remove shortage. And Spidey why you asked that check Resistance the coils with Ground? Plz plz plz anyone can help me that how can i remove shortage. . . I think i've checked the whole motherboard for get rid off the shortage expect North bridge and south bridge. . . .
Plz anyone can help that how to do that?

[bowor]

Re: HP G62 +5VPCU and VIN shorted

Hi all,
Hey Bowor, I've checked ISL6262, it is ok. not shorty, I'm very upset that how to remove shortage. And Spidey why you asked that check Resistance the coils with Ground? Plz plz plz anyone can help me that how can i remove shortage. . . I think i've checked the whole motherboard for get rid off the shortage expect North bridge and south bridge. . . .
Plz anyone can help that how to do that?

now, where the condition motherboard short? is it still on track vpcu +5, or where? I am usually to handling his is short, by injecting gave the 5v voltage, if it is short on the 5v line (see schematics). then I feel around the area where a hot hand. it usually causes short.

if no vpcu +3. could be caused from ec. try to re-solder all the legs ec. ec it works if you get a voltage of +3 v_aux_s5 derived from ic charger. easy way to check the voltage of +3 v_aux_s5 can pin battery, 1,7,8 feet of ic bios.


good luck!!!

[Francisco.s]

Re: HP G62 +5VPCU and VIN shorted

Plz plz plz anyone can help me that how can i remove shortage

.

I think i've checked the whole motherboard for get rid off the shortage

Why don´t you post your measurements?.
What about rt8206b, mosfets and caps around?

[sonunigam]

Re: HP G62 +5VPCU and VIN shorted

hi all,
I just want to know from all great and experienced technicians, that plz see the schematic diagram and help me out to solve this kind of shortage. I told to all of you that the shortage between +5VPCU and GND. I've a Multimeter which has a buzzer, When i connect Red and Black probe to each other, The buzzer is beeping. It's mean when +5VPCU is short with GND, the buzzer is beeping. . . Now tell me you all that how can i tell about the readings? Plz get rid me off from this mess. . . . .. I'm waiting for the reply.

[sonunigam]

Re: HP G62 +5VPCU and VIN shorted

One more thing that RT8206 is not generating 5v and 3v. Because the circuit is short. . . . .

[Francisco.s]

Re: HP G62 +5VPCU and VIN shorted

hi all,
I just want to know from all great and experienced technicians, that plz see the schematic diagram and help me out to solve this kind of shortage. I told to all of you that the shortage between +5VPCU and GND. I've a Multimeter which has a buzzer, When i connect Red and Black probe to each other, The buzzer is beeping. It's mean when +5VPCU is short with GND, the buzzer is beeping. . . Now tell me you all that how can i tell about the readings? Plz get rid me off from this mess. . . . .. I'm waiting for the reply.

You must use the ohms scale, not the buzzer. If readings are > 5 or 10 ohms, then there are no short-circuit.

[sonunigam]

Re: HP G62 +5VPCU and VIN shorted

Hi all,
Especially Francisco.s, Thanks for your great help. Now i checked with ohms and the PL4 is showing 00.2 Ohms. Now plz tell me what should i do? ? ?

[sonunigam]

Re: HP G62 +5VPCU and VIN shorted

Hey guys,
At last i got it, PC159 is faulty. but 3.3 or 5v are not generating by motherboard. Now i've to see more to find out why the Volts are not generating. . huh
BY the way thanks for your great replies. . .

[Francisco.s]

Re: HP G62 +5VPCU and VIN shorted

Hey guys,
At last i got it, PC159 is faulty. but 3.3 or 5v are not generating by motherboard. Now i've to see more to find out why the Volts are not generating. . huh
BY the way thanks for your great replies. . .

If 3.3 or 5v are not generating by motherboard, check +VIN on pin 2
of capacitor PC85 in order to know if PU5 is correctly powered.

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