Vaio VPCSB2M9E/PCG-41218M dead after drop

[Learn2Day]

Hi everyone,

This laptop is an absolute nightmare, it goes through 4 logic boards from charger/battery to power button. I can't find schematics online, this makes it impossible for me to follow anything. Maybe you guys can help me out.
The only thing I have working for me is that I have an exact same model working laptop to compare with. I have a big urge to replace board by board to figure out which board is busted and go from there but I'm afraid by doing this I bust both laptops..

It's completely dead from the drop, but apparently nothing seems cracked, except the body near the battery fit. I get 19V at charger input and 3.3V in a couple battery pins, but battery is not charging, also, laptop doesn't boot on a charged battery. This is pretty much it. I've rechecked all connections and hit the hard reset button just to be sure, nothing worked and now I'm lost..

Can you guys point me in the right direction?

Thanks in advance.

[Learn2Day]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

Here's some photos..

[atsio]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

Have a look at this.

[Learn2Day]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

Thanks for those schematics but something's not right..

Dunno if it's related to my board being rev 1.2 and schematics 1.3, but, in example, I followed 19V till PD12, in schematics PD12 is connected to ground. From PD12 i followed it to PU4 pin 10, not present in schematics..

What am I doing wrong??

Thanks.

[atsio]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

Which is PU4 on your board? Why are you following the over voltage protection circuit when you say your problem was a drop down and not a short? Do you have 19V on pin 5 of PQ14 or better 3.3 and 5v on PL16 and PL17?

[Learn2Day]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

PU4 is a CL257 TI, PQ14 and PQ15 have only 3 pins, 0V in all.
Can't find PL16 and 17, but i believe PL23 is where PL16 is suposed to be, it reads 1V.

I wasn't following the over voltage protection circuit, I was following the charger input! That's why i think the schematics are not the same.

Thanks.

[Learn2Day]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

Ok. I did a little more digging and apparently the issue is in the main board.
Dunno exactly how a drop turned into a common failure but the symptoms fit this thread.
https://www.badcaps.net/forum/showthread.php?t=29549
Motherboard black connectors are all shorted to ground.

This was the best solution i found, unfortunately I don't have a regulated power supply..

Hi guys!
I have just registered to share a bit of my experience with this mobo.
I had no power at all on this laptop (current draw was 0.01A when connecting the power adapter to the laptop). BTW, I am using a very convenient chinese cheap power meter to see what happens to the laptops when I connect them: http://www.ebay.com/itm/261219652805 .

I had the black connectors (in yellow rectangles) on the mobo shorted with each other and to the ground. Therefore, the power daughter board MBX-458 did not provide 19V to the shorted circuit.

Then I soldered regulated power supply terminals to the points shown GREEN. The voltage was set to 1.5V, the current to 3A. The capacitor in a RED rectangle became hot immediately. So, it was shorted to the ground. After I have removed it, all the shorts with black (6-pin and 10-pin) connectors went away. The cap was replaced by a compatible 10uF/25V ceramic cap, and laptop turned on, was assembled and passed to the customer.

Of course, in your case this can be ANY other cap or semiconductor, but the main method is the same: apply safe voltage (lower than the intended voltage for the shorted circuit) to the shorted circuit and slowly raise the current while controlling the temperature of the board (with your hands or using any pyrometer).

Good luck, colleagues, and successful repairs to you all! :-)

Is there any alternative to find which capacitor is shorted?

Thanks.

[atsio]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

Your short is on the 19v rail (r460 is upper fet on 5v rail, drain pins 5,6,7,8 are 19v) so you could try with your power supply (19v) but be carefull, if you see PCH is getting hot, stop it immediatelly, because a fet controlling a voltage rail to PCH is shorted (you pass 19v directly to PCH).
Remove cpu for test.

[lefos]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

Hello,

Check for the capacitor on the mainboard.That it's been said on that topic.
Also check on the small psu board there are some tiny fuses underneath those stickers.

[Learn2Day]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

CPU is soldered onboard. Tried with power adapter, no dice.

lefos, no fuses underneath the stickers, can't check capacitors on mainboard without injecting voltage. They're all parallel.

Thanks.

[atsio]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

When you try with power supply, can you check voltage and amps?

[Learn2Day]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

I can check voltage, not amps. 19V at DC input. To check current I would need to interrupt the circuit somewhere (obviously), and I don't want to go there because I've ordered a new 0-30V/0-10A regulated power supply which will be arriving this Tuesday or Wednesday, and this way I can measure amps directly before injecting signal.

Thanks.

[atsio]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

When you solder the power adapter cable on the cap you can check with a multimeter if you have 19v. Furthermore you can interupt the plus cable you solder on the cap with a multimeter to measure amps.

[Learn2Day]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

Doing that won't I risk busting the AC adapter? Also, in my experience, plugging the adapter to a shorted board, the adapter shuts down.. I can give it a try, but a power adapter is not stable as a power supply..

What if I use a desktop power supply and inject 5 or 12V instead? Won't that work best and more stable?

Thanks.

[atsio]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

If rail draws too much current (due to short) it will auto switch off. You can use a resistor to reduce amps drawn.
ATX power supplies provide a lot of current.

[Learn2Day]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

Yeah I thought about that, ATX says 45A on 3.3V.. Ouch! Is there any i can reduce my ATX 3.3V output to a steady 5A?
I'm a bit rusty on my U=RxI theories, but if I'm not mistaken a half ohm resistor in serial with the circuit should ensure to provide a 6.6A maximum current. What I'm unsure is if the full 3.3V will go through.

I'm very reluctant to inject 19V directly into the board from power adapter. I think more things could go wrong injecting such high voltage in the components..

Thanks.

[Learn2Day]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

Hey guys,

Today I got a new regulated power supply and I solved that shorted capacitor from the other thread. Now the main board is no longer shorted, but I still have no power...

I think this short must have busted something else in the power board. Now I'm back to following this:

PU4 is a CL257 TI, PQ14 and PQ15 have only 3 pins, 0V in all.
Can't find PL16 and 17, but i believe PL23 is where PL16 is suposed to be, it reads 1V.

I wasn't following the over voltage protection circuit, I was following the charger input! That's why i think the schematics are not the same.

atsio can you help me out?

Thanks.

[atsio]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

Your charger is BQ24725?

[Learn2Day]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

I'm not sure i understand your question.. I'm using one of two universal AC adapters I have in my bench. Is this what you meant to ask?

[atsio]

Re: Vaio VPCSB2M9E/PCG-41218M dead after drop

No the charger IC on the daughter board is BQ24725?