Compaq Presario CQ56 Quanta AX2 no power

[Techie666]

Hello all, I have this laptop that won't power on or do anything.
Using the following schematic; http://www.4shared.com/office/6ctmkt..._cq56_cq6.html

I took the following measurements:

Pq55 input=19.7v output= 28.8v
Pq58 pin 123 19.7v, pin 4 28.8v pin 5678 0v without the battery
PWRSRC 28.8V
VIN=18.7V

PU8 ISL6251A

Pin 1=5V (VDD)
Pin 2=2.1V (6251ACIN)(ACSET)
Pin 3=1.18V
Pin 8=2.39V
Pin 15=5v
Pin 19, 20 =19.74v
Pin 23=0V ACOK#
Pin 24 18.55v DCIN

PU6 (RT8206b)

Pin 1=2v (ref)
Pin 3=4.98v (VCC)
Pin 4=14.22V (ENLDO)
Pin 6=19.74V (VIN)
Pin 7=5v (LDO)
Pin 14=4.94V (ON1)
Pin 15=1.03V
Pin 16=0.01V

Pin 18=0V
Pin 19=5v (VDD)
Pin 23=0V
Pin 25=0.25V
Pin 26=0.1V
Pin 27=4.94V (ON2)

I lifted the following coils and measured
PL3 = 4.5 ohms on the side of +5 VPCU
PL10 = 10 ohms on the side of +3 VPCU
negative probe touching ground

these measurements in bars +5VPCU, +3VPCU have me confused, after I lifted the coils I suspect a short on both sides due to their low values , I still don't have any output from pins 25 and 16 from rt8206b

Kbc:
VCC = 0V
AD_TYPE = 0.50v
AD_AIR = 0.50v
Bios is not getting any voltage

Can anyone comment on my measurements? should I replace rt8206b considering the low resistance in the+5VPCU, +3VPCU lines?

Thank you for your attention.

[spidey]

Re: Compaq Presario CQ56 Quanta AX2 no power

Change rt8206b. voltages seems ok. Also change mosfets. Be carefull for the replacement, rt8206a and b not always interchangeble.

[Sebas3124]

Re: Compaq Presario CQ56 Quanta AX2 no power

the signal AD_AIR in normal conditios is +/- 2.6 volt, in my personal opinion your problema can be in other system, i was repair the same board whit similar problem, i will find the problem into pq 44 and pq 48, the power system manager of this board is very complex