Laptop totally dead, where to start?

[bicalov]

I have a next Sony VPCEB2SE1/BQ which is totally dead.
19,5V present, but no 3V and 5V.
Can somebody explain where the voltage rail starts and goes?
Thanks

[bicalov]

Re: Laptop totally dead, where to start?

measurements: page 71

PQ1 pin 1,2,3 = 18,92v pin 5,6,7,8 = 19,44V pin 4 = 18,89V

PQ2 pin 1,2,3 = 18,91V pin 5,6,7,8 = 0V pin 4 = 18,91V

PQ3 pin 1,2,3 = 0V pin 5,6,7,8 = 0V pin 4 = 0V

Where to go from here? Do I look for short in the capacitors between PQ2 and PQ3?

[dellxps15]

Re: Laptop totally dead, where to start?

pu19 check voltage at pins: 6, 14, 27, 4, 13, 28

[bicalov]

Re: Laptop totally dead, where to start?

Thanks for your response.
All pins on U19 show 0V
Only pin 28 show 0,86V stepping down to 0V in 5 seconds

[dellxps15]

Re: Laptop totally dead, where to start?

u must have short on 19volt rail somewhere..... voltage at pq69, pc187,

check also without power supply and with multimeter if there is short on that component.
pc187, pq69.

[bicalov]

Re: Laptop totally dead, where to start?

Voltage on all pins 0V
Multimeter in diode-position: pc187 both sides 0,00
PQ69: pin 5,6,7=0,56 pin 1=0,40 pin 4=0,90 pin 8= 0,00

Multimeter in Ohm position: pc187 both sides 0,00
PQ69: pin 5,6,7=3k pin 1=100k pin 4= 85k pin 8=0

[highpulse]

Re: Laptop totally dead, where to start?

bicalov , you must follow in charger area (schematic) the starter mosfet , it will stop in one of them , on the mosfet that stops , simply bypass to chek what is in short
specially it will be near cpu , as they usually blow easy (ceramic caps)

[bicalov]

Re: Laptop totally dead, where to start?

Thx highpulse.
I did that in the start of this thread, but which one is the starter mosfet?
And what is the best way to check the ceramic caps?

[bicalov]

Re: Laptop totally dead, where to start?

Value ceramic caps:
With multi meter resistance to ground in Ohm

PC152=0,5 pc163=8 pc167=8 pc199=2k8 pc203=10k pc208=16 pc212=15

pc238, 239, 240,241,244 = 75

[bicalov]

Re: Laptop totally dead, where to start?

I desoldered PC152, pc163, pc167, pc168, pc169 and pc171.
None gives a short.
What to do now?

[bicalov]

Re: Laptop totally dead, where to start?

bicalov , you must follow in charger area (schematic) the starter mosfet , it will stop in one of them , on the mosfet that stops , simply bypass to chek what is in short
specially it will be near cpu , as they usually blow easy (ceramic caps)

Tried to bypass mosfet PQ2 , burt only the ATI GPU got warm. The power supply was switching on and of and when on 2,32Awent through the board.
Futhermore no hot component to find.

[dellxps15]

Re: Laptop totally dead, where to start?

check if gpu coil is shorted.

edit: if u can u can also put back all mosfet, remove gpu coil and see if pc power on. if yes gpu need reballed-changed with new one.

[bicalov]

Re: Laptop totally dead, where to start?

check if gpu coil is shorted.

edit: if u can u can also put back all mosfet, remove gpu coil and see if pc power on. if yes gpu need reballed-changed with new one.

Sorry, forgive my ignorance, but what is the gpu coil ?

[dellxps15]

Re: Laptop totally dead, where to start?

inductor pl7. check if it's shorted.

[bicalov]

Re: Laptop totally dead, where to start?

PL7, 8,5 ohm to ground both sides.

Removed PL7 of the board, no change.

[bicalov]

Re: Laptop totally dead, where to start?

measured PU3:
pin 1 = 3,28V
pin 4 = 18,86V
pin 5 = 2,75V
pin 6 = 1,16V
pin 8 = 2,7V
pin 10 = 3,28V
pin 11 = 3,28V
pin 12 = 1,05V
pin 28 = 18,86V
All other pins = 0V

[bicalov]

Re: Laptop totally dead, where to start?

Hey, where is everybody???

[bicalov]

Re: Laptop totally dead, where to start?

A somebody pls take a look at the following pages?

page 71, short(0V) after PQ2 pin 5,6,7,8 is connected to DCBATOUT (PC128 group is ok, but shows short)
page 75, short measured at PC168,169,171 and again connected to DCBATOUT
page 76, short on PC152, connected to +1_5VSUS, but with PQ57 also to DCBATOUT.
page 80, low resistance (8 ohm) on PC163,,167 and via PQ43 also to DCBATOUT

Can you pls give me a lead how to follow up on this issue?

[bicalov]

Re: Laptop totally dead, where to start?

The DCBATOUT seems not to be the case, on page 76, the +1_5VSUS get involved.
When I disconnect PL6 on the right side (PC152), the system shows some reaction.
When pressing the on/off switch, the power led and the battery led light up for a moment, while the power led blinks twice.
On pin 5,6,7,8 of PQ57 is 19,46V , pin 1,2,3,4, = 0V. On PQ57, all pins are 19,45V.
PU13 shows pin 5 = 0V, pin 8,9,10 = 19,45V, pin 5= 0,15V.
Voltages show a little reaction (0,3V) when power switch is pushed.
Power switch now has 3,28V. When I put back PL6, everything 0V again.

Any advise will sure be appreciated

[dj_ricoh]

Re: Laptop totally dead, where to start?

you got a short to ground.

trace it. Continuity test

a SVF15 and SVF14 one Hour both.
found a short, injected voltage and found what was bad