| Ремонт: Ноутбуков, Компьютеров https://vlab.su/ |
|
| asus g750 (asus) shorting charger https://vlab.su/viewtopic.php?f=40&t=57346 |
Страница 1 из 1 |
| myth77 [ 17 фев 2017, 12:07 ] | |
| Заголовок сообщения: | asus g750 (asus) shorting charger |
I have asus g750 that is shorting charger. Everytime i put the charger i hear like ticklinkg sound and lights on charger is gone. I tested the charger with multimeter but it is ok. I stripped the laptop, removed everything, even a cpu but still shorting. Any help to determine what is wrong? i dont know how to test the motherboard without charger being plugged... |
|
| gs84 [ 17 фев 2017, 13:26 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
myth77 писал(а): i dont know how to test the motherboard without charger being plugged... you need to measure resistance relating ground at the input circuits
|
|
| myth77 [ 18 фев 2017, 22:54 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
Can you please explain in more details...when i connect black wire of multimeter to ground and red to diodes or mosfets near the power circuit i mostly get reading near 0.20 ohms...what should i look for? |
|
| myth77 [ 21 фев 2017, 13:46 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
Ok i am a big noob :) but please help, i wont to learn... I downloaded boardview and checked resistence with multimeter (offcourse with power supply off) and i found out that probobly in this red part attached there is a short. On boardview in this part where is a ground i find resistence relating ground but resistence is also found on the other side of components relating ground where it should not be. For example on that POSCAP capacitor near the mosfets..one leg is ground....i found resistence relating ground but also on other leg of capacitor AD dock in there is resistence to the ground. I checked other parts of the motherboard and resistence relating ground are only read on ground components, where it should be. So...can you help me determine what to do next? to find faulty component...i am attaching also boardview. |
|
| gs84 [ 22 фев 2017, 11:50 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
measure resistance here. I picked for you the ground, don't need to find complexity ways to found it |
|
| myth77 [ 22 фев 2017, 23:17 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
Thank you very much, i attached the picture with explenations. As you can see i read resistence relating ground on all blue (as it should be, cause they are ground)...but also in all red where i believe it shouldnt be. I checked also that resistor that you pointed, PR8806 and i have a reading of 00.4 ohm relating ground and ofcourse continuity. So you believe that it is this resistor that is shorting the charger? if yes, can you please explain why? thank you. And if yes how to tell that it is only part that is broken? i shoud remove it and check resistence again on these part of the motherboard, without it attached? |
|
| gs84 [ 22 фев 2017, 23:57 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
myth77 писал(а): i shoud remove it and check resistence again on these part of the motherboard, without it attached? yes, do itmyth77 писал(а): if yes, can you please explain why? I don't know how to explain you in few words, because you must know principles of input DC circuits in laptops.
|
|
| myth77 [ 23 фев 2017, 00:49 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
ok i remove it...but nothing...still continuity and resistence on all red parts of the motherboard except the other line 1 of this resistor (p_chg_path 19v). Although, the reading of the resistence on ac_bat_sys relating ground is now around 02.4 ohm. I even tried to put the charger/adapter to check but still shorting. Any suggestions on what to do next? Also, regarding your second answer i believe i understand principles of dc input circuit..so..let me try for a noob, just a basics :)...From one part of the charger there is current coming through the motherboard with power of 19V, and regardles of the chip, cpu, graphic card...it uses the diods, capacitors, resistors, mosfets...to modify the current to lets say for example 5V cause the usb controller chip needs 5V (this is example)...the negative current is just part of the all current that is "coming back" to charger and so on but its needed so it can make complete circle... electricity coming one way and going other...In the end the negative current its just a part of the circle that connects motherboard in a big circle of power. The ground is something if needed (shorted) is used for taking electricity from the laptop-current to the ground...lets say in short circuits so it would not do any damage or so on :) Did this make any sense that i wrote? please if am wrong correct me? :) All other nets inside the motherboard are just separate connections from chips to lets say video card, audio card...and so on... So i figured that there is somewhere short in my motherboard that is connecting positive current to the ground because of some resistor or something else is broken. But, how to determine which one? |
|
| gs84 [ 23 фев 2017, 17:56 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
myth77 писал(а): ok i remove it...but nothing what you mean? I asking about shorting at the resistor. After desoldering one shorting still before that resistor or after?
|
|
| myth77 [ 23 фев 2017, 18:57 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
I desoldered the resistor and measured resistence on motherboard relating ground with multimeter ...but i get short everywhere like before. So after desoldering i get same short to the ground everywhere on that red marks, just as before desoldering. I attached picture again.... |
|
| Elektronik388 [ 23 фев 2017, 19:02 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
Throw Laboratory power supply |
|
| myth77 [ 23 фев 2017, 23:26 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
I dont have it unfortunatelly :( |
|
| gs84 [ 24 фев 2017, 11:07 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
you mean, after desoldering that resistor you have shorting in point 1 and 2? check that input mosfets, do you know how to do it? seems, |
|
| myth77 [ 24 фев 2017, 13:49 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
no, shorting only on 2. On 1 there is no resistence relating ground after desoldering... |
|
| gs84 [ 24 фев 2017, 14:59 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
myth77 писал(а): no, shorting only on 2. On 1 there is no resistence relating ground after desoldering... so, that's why problem in 19v circuits. How to determine shorting see here
|
|
| myth77 [ 26 фев 2017, 22:14 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
So i have to use something like labaratory power supply?... something that will force the current even with short to ground, and will not activate protection like on charger/adaptor?...and then check what part is overheating?...hmmm i dont have labaratory power supply...can i improvise and use fully charged battery? Or part of the kid toy that is running on 4V? Can i solder the wires od the toy on motherboard and put 4V battery and check where is heating? Thank you for answer |
|
| gs84 [ 26 фев 2017, 23:41 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
myth77 писал(а): Can i solder the wires od the toy on motherboard and put 4V battery and check where is heating? yes, you can. But how you will limit power consumption?
|
|
| myth77 [ 27 фев 2017, 12:00 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
Hmmm i dont know...but will it be enough to test what part is heating? |
|
| gs84 [ 27 фев 2017, 21:12 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
myth77 писал(а): but will it be enough to test what part is heating? depend of the battery capacity
|
|
| myth77 [ 28 фев 2017, 12:27 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
what battery would you suggest? how many volts? arround 4V? and what rated capacity, mAh? If you could give me the link it would be nice :) Also, can you suggest where to solder, on what points on the motherboard? i attached the motherboard...can you point where would you solder + and where - wire of the toy battery? thank you! |
|
| gs84 [ 28 фев 2017, 14:40 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
viewtopic.php?p=420362#p420362 that picture, point 2 |
|
| myth77 [ 28 фев 2017, 15:30 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
both wires (+ and -) on point 2? |
|
| gs84 [ 05 мар 2017, 00:59 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
myth77 писал(а): both wires (+ and -) on point 2? I tired to explain you elementary things. Before laptop repairing each must be know how to find a short on a PCB.
|
|
| myth77 [ 07 май 2017, 17:55 ] | |
| Заголовок сообщения: | Re: asus g750 (asus) shorting charger |
Update...first thx everybody for help... It seems that it was IT8585E chip. After replacing there is no short to the ground...but now it will not start :) when i press power it does nothing. i can feel under my finger that D6002 esd protector is really heating a lot..any ideas where to go next? 
|
|
| Страница 1 из 1 | Часовой пояс: UTC + 4 часа |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|