Asus X550cc run only when jump first mosfet

[ktmmotocross]

Hello.
I have this Asus X550cc that run only when i jump first mosfet. All reading looks good/ACDET, ACOK, VCC/. i replaced two capacitors on gate of that first mosfet, i replaced second mosfet which was shorted, i replaced BQ ic, but still wont run.

Any advice for this board?

[petehall347]

Re: Asus X550cc run only when jump first mosfet

its bad or no drive to the gate ..maybe gate resistor high or open .

[piernov]

Re: Asus X550cc run only when jump first mosfet

Give the exact voltage on VCC, REGN, ACDET, ACOK, ACDRV, CMSRC, ACN of charger IC.

[ktmmotocross]

Re: Asus X550cc run only when jump first mosfet

Give the exact voltage on VCC, REGN, ACDET, ACOK, ACDRV, CMSRC, ACN of charger IC.

without jumped mosfet
VCC - 19.5V
REGN - 6.1V
ACDET - 2.6V
ACOK - 0V
ACDRV - pulsing
CMSRC - pulsing
ACN - pulsing 3-9V

with jumped first mosfet
VCC - 19V
REGN - 6.1V
ACDET - 2.62V
ACOK - 3.0V
ACDRV - 25V
CMSRC - 19V
ACN - 19V

[piernov]

Re: Asus X550cc run only when jump first mosfet

Measure exact resistance between ACN and ACP, and between SRN and SRP.

[ktmmotocross]

Re: Asus X550cc run only when jump first mosfet

have 0.5ohm ACN and ACP and 0.4ohm between SRN and SRP

[ktmmotocross]

Re: Asus X550cc run only when jump first mosfet

when jumped mosfet, if i connect power and than battery, it charging normal. when i connect battery and next power, it will go on HIGH consumption like 90W and 20W is normal

[ktmmotocross]

Re: Asus X550cc run only when jump first mosfet

this is weird. everything works BUT battery must be attached. without battery i have only 3-4V on VIN rail. I see some models without RTC battery that wont work without main battery, but this board have RTC battery on board/3V/ but wont even power without battery

[DavidThijs]

Re: Asus X550cc run only when jump first mosfet

Have the same issue here with an ASUS N76V v2.2 mainboard.
Have replaced both mosfets with A5 GNE/GNC/GNB like.
AC_DRV gets a pule every 1.3s and at the current shunt, you will see a 19v peak which goes directly down.

It does run fine on a charged battery. When applying DC alone, it draws almost no current (psu says 0.03W every 1.3s).

I'm suspecting the charge pump of the battery controller but no schematics or any sourc e of testpoints is available.

[DavidThijs]

Re: Asus X550cc run only when jump first mosfet

Attached scope images of each of the 20 pins of the battery controller.