Packard Bell EasyNote TK 85 doesn t start

HI all, I have an Packard Bell EasyNote TK 85 which doesn't want to power
on, no led light, all dead.
The motherboard PCB marking Code ies:

PEW91 LA-5894P rev. 1.0

I had checked the power supply, the fuses are good, 19V from the adapter
are present. the first 2 P channel mosfet(PQ 51, PQ 52) are working let pas the 19V. I
measured some voltage on the borad and I found nothing ( PL 27=0V, PL 28=0
V), I do not have 5V or 3V.

The battery charger controller (ISL 6251) is not supplied(VDD=0V), no
voltage inside the motherboard .

Two mosfet have 6 Ohm between sourse and drain (PQ35,PQ36), this is normal?

What I should check?

Best regards!

Measure the resistance at PL27, PL28.
Measure the tensions at PU16 - outputs 4, 6, 7.

Resistance of PL27=0.01 ohm, PL28=0.01 ohm
Voltages at PU16:

PIN 4=0V
PIN 6=19V
PIN 7=0V

Measure the voltages on pins 1, 3, 8, 10, 15, 16, 24 of PU17.
Measure the voltages on all pins of PQ54.

Voltages on the PQ54 transistor
gate(pin 1)=19,03V
drain (pin 2)=0V
source (pin 3)= 19,03V

Voltages ,at PU17:
Pin 1=0V
pin3=0V
pin 8=0V
pin 10=0V
pin15=0V
pin 16=0.24V
pin 24=0V

Measure the voltages on all pins of PQ51, PQ52, PQ56, PQ58, PQ59, PQ56, PU18.

Hello,

I measured the following voltages:

PQ51:
- pin 1,2,3 = 19,48Vcc
- pin 4 = 1,42 VCa, 8,25 Vcc
-pin 5,6,7,8 = 18,48 Vcc

PQ52 :
-pin 1,2,3 = 19,48Vcc
-pin 4 = 1,42Vca 8,25VCC
-pin 5,6,7,8 = 19,48Vcc

PQ56:
- pin 1=17,6Vcc
- pin 2 = 19,39Vcc
- Pin 3=7,97Vcc

PQ 58
pin 1=0V
- pin 2=0V
- pin 3 = 0V

PQ 59:
- pin 1= 2,72V
- pin 2 = 0V
- pin 3 = 0V

I didn t found PU 18 at this board, what is his name?

Best regards!

PU18 is working.
Do the test described here on PL27, PL28:
post5699.html#p5699

PL 27 = 0V
PL28 = 0V

What i should check?

Resistance of PL27=0.01 ohm, PL28=0.01 ohm

Inserted in the link there is a tutorial that explains how to inject a voltage to detect the short circuit of PL27, PL28.

Where is the link, i cannot see it?