HP 425 No power

[Techie666]

Hello fellow members, here I am again with a lappy pretty dead to my taste but it gives me the opportunity to learn a little with it.

It's an HP 425 Motherboard 6050a2364501-mb-a03
the closest schematic I could find is this http://www.4shared.com/office/3C4ITYw1/ ... 5_cq3.html

Even though it does not match 100% it's helping me id. the connections of some components but not all.

To the point, when connecting the charger to the computer, the LED on the dc connector turns on and is fixed and never goes out, with and without battery does the same
if I connect just the battery the LED lights come on as if it were charging the battery without the charger

Pressing the power button does nothing.

some measurements so far:
L507 18.68v
Q9862
PIN 1,2,3 = 18.62V
PIN4 = 18.29V
PINS 5-8 = 0V
D501 = 0v both pins
Q505
Pin 3 (D) 18.12V
Pin 1 (G) 0v
Pin 2 (S) 0v (ground)
U503 (BQ24740)
Pin1 = 2.84V
All other pins 0v

none of the standby voltages are present after Q9862
the power button has 3.3v

I will continue looking for the right diagram, if someone has it please share!!
In the meantime I would be very grateful if someone can give me a hand to follow up on this mother.
greetings and thanks.

[Tuomo]

Re: HP 425 No power

Hello fellow members, here I am again with a lappy pretty dead to my taste but it gives me the opportunity to learn a little with it.

It's an HP 425 Motherboard 6050a2364501-mb-a03
the closest schematic I could find is this http://www.4shared.com/office/3C4ITYw1/ ... 5_cq3.html

Even though it does not match 100% it's helping me id. the connections of some components but not all.

To the point, when connecting the charger to the computer, the LED on the dc connector turns on and is fixed and never goes out, with and without battery does the same
if I connect just the battery the LED lights come on as if it were charging the battery without the charger

Pressing the power button does nothing.

some measurements so far:
L507 18.68v
Q9862
PIN 1,2,3 = 18.62V
PIN4 = 18.29V
PINS 5-8 = 0V
D501 = 0v both pins
Q505
Pin 3 (D) 18.12V
Pin 1 (G) 0v
Pin 2 (S) 0v (ground)
U503 (BQ24740)
Pin1 = 2.84V
All other pins 0v

none of the standby voltages are present after Q9862
the power button has 3.3v

I will continue looking for the right diagram, if someone has it please share!!
In the meantime I would be very grateful if someone can give me a hand to follow up on this mother.
greetings and thanks.

First 3VA and 5VA always voltages U519 have to works.

Check those voltages.

[Techie666]

Re: HP 425 No power

Hi Tuomo, thanks for your reply.

I think you mean +V3A and +V5A

I have checked U519:

U519 (RT8205)
Pin 17=5V (VREG5)
Pin 16=17.97V
Pin 15=0V (ground)
Pin 14=2.0V
Pin 13=4.30v
Pin 11=0V (+V3A)
Pin19=0v
pin 20=0V (+V5A)
Pin8 3.33v (VREG3)

problem was I had no +VBAT

I also didn't have the signals KBC_PWR_ON, ADP_EN.

kb has 3.3v at vcc1
Pin 60=0v
Pin 75=0v
Pin 77=3.3v
Pin 68=3.05v

what has changed?

I removed spi flash and tried flashing with sp52014.exe with has 68DVA.bin

now when i connect ac, the led stays off, if I push power button, fan spins, lights come on and laptop starts but still no boot and no video. it stays on for a few seconds, charging light flashes 10 times and then everything goes off.

now I have:
+VBAT=18.10
+V3A=3.40v
+V5A=5.00v

I think I need a good bios dump for HP 450
I'll keep posting

[laptech]

Re: HP 425 No power

plz send hp450 bios bin file