My Sony Vaio Laptop Won't Power ON???

[viranj]

Hi..
I am Using Sony Vaio Model No: VGN-FE45G/W.

in Iam working with my Laptop Suddenly Keyboard failure.
In keyboard Any Keys Cannot Operate it. So I use Some Days With External Keyboard. Recently Power Off my Laptop. Cannot Power On again. i Try So many Ways to try start. Battery Removed apply D.C adapter power. Nothing Happened. Battery Power Apply and On Again. Nothing Happened. I try Cmos Battery Jack Remove and Pushed again,. Nothing Happened.

No Leds on No Noises, No Beep Sounds, No Screen Blinking.

D.C Adapter Working. Battery Working. Main Board Removed and Applying D.C Adapter . In Conncted D.C. Adapter Jack I check Voltage With Multimeter. It Shows 19.5 Voltage. so Voltage pass O.k.

IN Main Board is Fault. How to Rectify that. How Can i Find Out Problem in Main Board.


few details about my Laptop.

Sony Main Board Version is MBX 149 (MS 13, Rev 1.1)


(I have Little Bit Experience In Hardware Basics , and i have schematic above this Main Board)

PLease Help us. what to do??? How to Check voltages components in Main board with multi meter to find out Problem.

Thank You.

[Skimask]

First of all, you pull out everything, ram, drives, anything and everything that can easily be pulled out, and try again.
Then you figure out how to get the "beep codes" from the BIOS.
After that, you go on ebay, look for an identical model for dirt cheap, and buy that rather than wasting your time trying to fault find.

[SpidersWeb]

I agree, if removing the extras like the battery does not help, and you can't see an obvious fault inside, just replace it.

One thing I will say though, is the internals structure of some laptops aren't the best - for example one model I did repair (common fault) was an old Toshiba which had insufficient support under the keyboard. Ever since it was new, every person who rested their palms on it, was actually slightly putting weight on one of the main power connectors - until one day - no more power ups.

I mention this because it might be worth looking inside for any connectors which may have been exposed to stress.

To fix the fault on the old Toshiba all I did was run my soldering iron past the tiny connectors causing it to reflow the solder.
(NB: there are lots of other things it could be, this is just one thing to think about, since the keyboard died while you were typing)

But I never diagnosed the fault - I guessed and it worked.

[miguelvp]

Reseating the memory modules might bring it back to life. I had a system with no Post codes and no video, on board LED was green, swapped video cards problem remain until I took the memory out and place it back in. Then it was back to life.

[viranj]

I am already Removed All components from Main Board. I try to Find on ebay and Amazon my main board. But Suggested Model Not Available at present.

and My Main Board Problem Is Small. cannot ON the Power.?

how to find out the Problem . Just it.... 

[miguelvp]

It doesn't make a series of beeps on boot?
That will be the POST code error if any.

Without the memory it won't boot at all btw.

[viranj]

first power failure before stuck at booting.  and after than i restarted again laptop A.C Led blinking on Laptop after than gone out completely.

No Beep Sounds. No display On. No Led's On.

I checked voltage on Mother board it will displays 19.5 volts at D.C. jack input. And checked power button voltage it shows 5 to 6 volts. some thing missing voltage i
n power button.??

[Wytnucls]

Make sure the fan is rotating. My Vaio Z1 shuts down immediately if the fan is stuck.

[amyk]

Make sure LDO3 (ECVCC) and LDO5 outputs of the MAX8734 are OK. The EC (KB3910) should receive power and then shortly afterwards turn on the 5VALW/3VALW supplies via ALW_ON.

[viranj]

I Checked outputs Voltages in Max8734. It shows LDO3 2.22v and LDO5 3.20 volts.

[Rasz]

diagrams so others can see it too
http://kythuatphancung.vn/download/sony-vaio-fe880e-foxconn-ms13-mbx149-laptop-schematics.html?dl

>LDO3 2.22v

should be 3v

>and LDO5 3.20 volts.

should be 5v

where did you measure those? after some mosfets of directly on inductors?
Max8734 ALW_PWRGD?




'Sony MBX-149 VGN-FE motherboard with GO 7600'

well, there is your problem, If you didnt measure voltages I would just said GPU needs to be replaced, but you say keyboard died first , so its something else

[xtv]

Have you tried to power it on with the keyboard disconnected?

Its possible that the power/volume/function buttons uses the same bus as the keyboard, and the bad keyboard are preventing it to work.

Either way, these voltage lines you've measured are unacceptable.

Did you put a proper load in your power supply adapter while measuring it? It may be providing 19v with no load, but may drop with your laptop load.

[viranj]

diagrams so others can see it too
http://kythuatphancung.vn/download/sony-vaio-fe880e-foxconn-ms13-mbx149-laptop-schematics.html?dl

>LDO3 2.22v

should be 3v

>and LDO5 3.20 volts.

should be 5v

where did you measure those? after some mosfets of directly on inductors?
Max8734 ALW_PWRGD?




'Sony MBX-149 VGN-FE motherboard with GO 7600'

well, there is your problem, If you didnt measure voltages I would just said GPU needs to be replaced, but you say keyboard died first , so its something else

I did measure those Voltages on Max 8734.  LDO3 pin no: 25 . it displays 2.22 v. and LDO5 IS Pin No:18. It Shows 3.20 Volts.

where is the power voltages missing.??

[viranj]

Have you tried to power it on with the keyboard disconnected?

Its possible that the power/volume/function buttons uses the same bus as the keyboard, and the bad keyboard are preventing it to work.

Either way, these voltage lines you've measured are unacceptable.

Did you put a proper load in your power supply adapter while measuring it? It may be providing 19v with no load, but may drop with your laptop load.

Yes.

I check D.C adapter Voltage it Shows 19.5 Volts With / With out load. adapter works Perfectly. i checked after connected on board D.C Voltage it shows 19.5 v.

power/volume Buttons are separate and functions works perfectly. only Problem is Keyboard and Power On .

[amyk]

Is the MAX8734 getting hot? If it is, then something is shorting out the LDOs (they can only supply 100mA max), otherwise it could be defective or the internal reference that supplies the LDOs is - check the REF pin too (across PC301 would be a good place), there should be almost exactly 2V on it. Note that as the datasheet says, there cannot be more than 100uA drawn out of this pin or the voltage will sag.

[viranj]

Is the MAX8734 getting hot? If it is, then something is shorting out the LDOs (they can only supply 100mA max), otherwise it could be defective or the internal reference that supplies the LDOs is - check the REF pin too (across PC301 would be a good place), there should be almost exactly 2V on it. Note that as the datasheet says, there cannot be more than 100uA drawn out of this pin or the voltage will sag.

No hot on max 8734 . Its cool. and i Checked again REF Pin PC301 there should exactly 2.01v. and again checked LDO3  PIN no.25 IT SHOWS 3.40V AND LDO5 PIN no.18 IT SHOWS 5.11 V. On it. Alw P Good Pin no.2 It Shows 3.37 v.

and Pin NO 3 alw on 3 it shows 3.34 v. and same again Pin no 4 On 5 it shows 3.34V.  How it is???

i checked every LDO'S, ALWON AND PGOOD pins 4 to 5 times.

[Rasz]

 todays measurements are with smps running (after pressing power on button, on3=on5=3v), at this point ldo3/ldo5 is using smps and can supply more current

at least we know it starts

KB3910 is responsible for run_on/run_on1 signals that turn on mosfets redistributing power around. Does KB3910 get enough voltage on its vcc? it should be connected to LDO3, does it get hot?

did things like battery charge led work after keyboard initially died? do those leds work now?

[Stonent]

If it has an Nvidia video chip the problem is almost certainly there. Those are known for thermally stressing the RoHS solder and cracking it.  You can many times bake the board to reflow the solder.

[Rasz]

measure everything twice, before and after pressing power button

unplug cmos battery

measure j2 (rtc_rst)
check:
d21  schottky
c721/c723
pc327
pd35


c793 794 798 796 797
q102
c804 c1306
c806
etc, basically every capacitor connected to ecvcc


Stonent GPU usually doesnt prevent from starting, on vaio its KBC or power rails.

[viranj]

todays measurements are with smps running (after pressing power on button, on3=on5=3v), at this point ldo3/ldo5 is using smps and can supply more current

at least we know it starts

KB3910 is responsible for run_on/run_on1 signals that turn on mosfets redistributing power around. Does KB3910 get enough voltage on its vcc? it should be connected to LDO3, does it get hot?

did things like battery charge led work after keyboard initially died? do those leds work now?

Where can I check Voltages are Run_on/Run_on1. in KB3910 or Max8743(Pu3).

I check Those chip Pins In KB3910

Run_on= Pin no:162 -  0.00v

Run_on1=pin no:148 - 0.00v

Ecvcc pin no: 161..  3.34v

Ecvcc  Pin No: 16... 3.34v

and Max8743 (pu3)

Run on pin no  11...0.00v
Run on1 pin no12...0.00v

No heat on Chips.. KB3910 and Max8734 .

and battery Charge Led and Power On led 's Working after Keyboard is dead.

at now No led's ON. No LIghts are Blinking. No Beep Sounds.

[Rasz]

measure everything twice, before and after pressing power button !!one7

I check Those chip Pins In KB3910
Ecvcc pin no: 161..  3.34v
Ecvcc  Pin No: 16... 3.34v

pin.95?

and battery Charge Led and Power On led 's Working after Keyboard is dead.
at now No led's ON. No LIghts are Blinking. No Beep Sounds.

no charging or ac led suggests EC (KB3910) not working at all now, either its not powering up due to power/bios, or its dead

oh yeah, check voltages on the bios chip, I think EC loads its own firmware from there

You might try just replacing ec outright (3-5 bucks with long shipping)
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H0.XKB3910SFC1&_nkw=KB3910SFC1&_sacat=0

again, re measure ldo3/5 after unplugging battery and ac and without pressing power, is it still really 2v/3v?  if it is and you have hotair then lift EC from the board and measure again

[Stonent]

Stonent GPU usually doesnt prevent from starting, on vaio its KBC or power rails.

It's very common on Dell and HP.

[Rasz]

Stonent GPU usually doesnt prevent from starting, on vaio its KBC or power rails.

It's very common on Dell and HP.

no its not, bad gpu will deffo prevent booting, but not block at least starting power rails / blinking some leds
bad nvidia gpus go upen, not short

[viranj]

pin.95?




pin no.95 .....3.36V

[viranj]

measure everything twice, before and after pressing power button !!one7

I check Those chip Pins In KB3910
Ecvcc pin no: 161..  3.34v
Ecvcc  Pin No: 16... 3.34v

pin.95?

and battery Charge Led and Power On led 's Working after Keyboard is dead.
at now No led's ON. No LIghts are Blinking. No Beep Sounds.

no charging or ac led suggests EC (KB3910) not working at all now, either its not powering up due to power/bios, or its dead

oh yeah, check voltages on the bios chip, I think EC loads its own firmware from there

You might try just replacing ec outright (3-5 bucks with long shipping)
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H0.XKB3910SFC1&_nkw=KB3910SFC1&_sacat=0

again, re measure ldo3/5 after unplugging battery and ac and without pressing power, is it still really 2v/3v?  if it is and you have hotair then lift EC from the board and measure again

KB3910 PIN No.95.....3.36V

again i rechecked again LdO3 ...3.34V AND LDO5 ....5.11V AND REF PIN 2.01V. These values checked only With A.C Adapter and Without Pressing Power Button.

When Internal Keyboard is Dead.  after i am working with External Keyboard 2 to 3 Months. Recently Power Failure Problem Occured.



Run Power voltage is Missing???    RUN_ON..0.00V  RUN_ON1...0.00V. IN MAX8743. PwGood PIN NO:7 ALSO 0.00V.