• Asus F555L (no led, no power on) Main X555LD Rev 3.3

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#1 Asus F555L (no led, no power on) Main X555LD Rev 3.3


by robgerr 22 October 2020, 12:50
good morning friends of the forum. This laptop enters the laboratory with the defect that it does not turn on, no leds. Connecting it to the bench power supply I don't read any absorption. There are no traces of oxidation. In the battery connector there are no 3.3v of the sda ​​scl lines for charging. I tried to reprogram the bios with several dumps found on the net and with the reprogramming of the bios I have a small absorption of 0.01A and 3.3V now appears on the battery connector (SDA SCL for charging)

Re: Asus F555L (no led, no power on) Main X555LD Rev 3.3


by Google Adsense [BOT] 22 October 2020, 12:50

#2 Re: Asus F555L (no led, no power on) Main X555LD Rev 3.3


by matic 22 October 2020, 13:42
Hello!

Measure the voltages to ground on coils PL8100, PL8101.
Measure the voltage to ground on pin 6 of chip PU8100.
Measure the voltage to ground on pin 5 of chip PU8800.

#3 Re: Asus F555L (no led, no power on) Main X555LD Rev 3.3


by robgerr 22 October 2020, 13:49
Hi Matic ;)
PL8100 2,48V
PL8101 0,08V
PU8100 PIN 6 0V
PU8800 PIN 5 3,03V

#4 Re: Asus F555L (no led, no power on) Main X555LD Rev 3.3


by matic 22 October 2020, 15:37
Measure the voltages to ground on pins 14, 15 of chip PU8100.

#5 Re: Asus F555L (no led, no power on) Main X555LD Rev 3.3


by robgerr 22 October 2020, 15:41
pin 14 5V
pin 15 3,30V

#6 Re: Asus F555L (no led, no power on) Main X555LD Rev 3.3


by matic 22 October 2020, 16:11
Measure the voltages to ground on pins 12, 17, 19, 35, 57, 74, 77, 85, 86, 96, 109, 111 of KBC chip.

Measure the voltages to ground on pins 56, 110 of KBC chip in the following cases:
a) Power button released.
b) Power button pressed.

#7 Re: Asus F555L (no led, no power on) Main X555LD Rev 3.3


by robgerr 22 October 2020, 16:23
PIN 12 1,81V
PIN 17 3,30V
PIN 19 3,27V
PIN 35 2,48V
PIN 57 2,48V
PIN 74 3,29
PIN 77 3,29V
PIN 85 3.29
PIN 86 3,29V
PIN 96 3,29V
PIN 109 3,26V
PIN 111 3,30V
PIN 56 3,24V,on power button pressed stay 3,24V
PIN 110 3,27V, with power button pressed drop to 0v and go up to 3,27v when release power button

#8 Re: Asus F555L (no led, no power on) Main X555LD Rev 3.3


by matic 22 October 2020, 20:25
Reflash the KBC chip with programmer. Don't forget to save the old dump.

#9 Re: Asus F555L (no led, no power on) Main X555LD Rev 3.3


by robgerr 22 October 2020, 23:35
i can't find a kbc dump for revision 3.3
*** update ***
I tried in every way to read the kbc rom but svod always gave me the error Ite is busy. Usually these kbc in the asus are programmed automatically if they are new and after the first power on, I soldered a new kbc, I left the main board powered for 10 minutes and trying to give the power on nothing happened, I did the measurement again on the pin 56 where I find 3.24V but if I give the power on it always remains fixed at 3.24V

Re: Asus F555L (no led, no power on) Main X555LD Rev 3.3


by Google Adsense [BOT] 22 October 2020, 23:35
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