Dell Alienware 15 LA-C912P REV2.0 No Power

[RiTCH50]

Hi folks hope somebody can help!

Dell Alienware 15 LA-C912P REV2.0 laptop here that I have No history of. Don't know what previous has happened just dead no power at all.
The only thing I can find is what looks to be a burnt resistor? I cannot see the value, have attached the pic.
The laptop does not power at all, nothing. There is 19V at 1 side of the resistor, 0.89 at the other.
Any pointers would be amazing please!

Thank you and good health, Rick

 

[RiTCH50]

I'm sorry I cannot insert picture?

 

[RiTCH50]

https://ixxxxxxxxx

This is link to the image

 

[Admin]

bq24780s pins
VCC !!
ACDET !!
ACOK !!
ACDRV !!

 

[RiTCH50]

Hi Thank you I'm super noob :-(
Spoon feed possible??!!

 

[RiTCH50]

bq24780s pins
VCC !!
ACDET !!
ACOK !!
ACDRV !!

I found this hope you can help me

pin 28 vcc 0.86v
pin 6 acdet 2.57v
pin 5 acok 0.19v
pin 4 acdrv -0.05v

 

[RiTCH50]

Just thinking out loud here but the data sheet states:
---

VCC 28 Input supply from adapter or battery. Use 10-Ω resistor and 1-µF capacitor to ground as a low pass filter to limit inrush current. A diode OR is connected to VCC. It powers charger IC from input adapter and battery.
---

I can't find a schematic for the mainboard and so would it be fair to assume that the required replacement resistor should be 10-Ω going of the TA datasheet??
Thank you and please forgive my ignorance!

Rick

 

[Admin]

-Pin 28 vcc MUST GET 19V When you are in use for the AC adapter :
check impedance between vcc pin28 and the ground how much you get.
-PQ702 check impedance between pin 5 and the ground .

 

[RiTCH50]

Thank you!
With no power to board I get 6.86k on pin 28 to ground
pq702...i'm not sure, counted up like charging a cap then went off?
Again both with no power to board

 

[Admin]

you need to check impedance between pin 5 fo pq702 and the ground .

 

[RiTCH50]

Thank you Admin -
I get 95.4 reading between pin 5 and ground when multimeter set to 200K.
(again no power to board)

Thanks,
Rick

 

[Admin]

CHECK
PR707 =10 OHM
PD700 = DIODE
on the pin3 of PD700 you must get 19V When you are in use for the ac-adapter .

 

[RiTCH50]

Hi Admin.
I replaced PR707 - it was burnt and now get 19V good.
Checked pin 3 of PD700, 19v good.
Board still refuses to power :-(

Thank you, Rick

 

[RiTCH50]

So... I just checked pin pin 6 acdet 2.57v on the chip side, 19.36v at the "other" side of the resistor PR716, This reads 247k - I beleve from much much googling that the value should be 324k?
Or I may be barking up the wrong tree!

Thank you Admin

 

[Admin]

bq24780s
pin 4 ACDRV !! how much you get on these pin .

 

[RiTCH50]

Hi
Nothing 0v on this pin.
Rick

 

[Admin]

change the ic of charge with a new one .

 

[RiTCH50]

I was worried you'd say that - i'll give it a go thank you!

 

[RiTCH50]

Hi
I changed PU700 - still same no power :-(

 

[RiTCH50]

Also I now get
ACOK : 0v
ACDRV: 0v

:-(