Toshiba c660 - NB burns instantly

[Learn2Day]

Hi guys,

Being green as I am, I'm having a huge headache on this laptop.
The laptop powers off in 3 sec. or less. The issue detected is north bridge (U11) heating up really fast, as soon as power is fed, either on AC or battery.
On AC i don't even need to power on, as soon as i plug in charger NB burns.

I'm afraid to power the laptop and test it, because i fear damaging the NB. If you guys could give me some pointers where to start testing I'd really appreciate it.

TIA, Cheers.

[spidey]

Re: Toshiba c660 - NB burns instantly

looks like your nb is shorted.reball or change it with a new one.

[Learn2Day]

Re: Toshiba c660 - NB burns instantly

Hi spidey,
Yes, it's obviously shorted, the question is where.
I did tried a reflow without success, I doubt a reball will make any difference and these chips endure quite alot. I doubt the issue will be there, I'm more inclined to a failure in the power module, can you help me test it in the right points?

Thanks.

[pra_j007]

Re: Toshiba c660 - NB burns instantly

The laptop c660 powers off in 3 sec. 3vand 5v coil ok but 3v 5v output mosfet q11 ,Q10 not ok ???

[Learn2Day]

Re: Toshiba c660 - NB burns instantly

Does your NB also heats up fast?

[whaldsz]

Re: Toshiba c660 - NB burns instantly

what is the voltage of your B+? Is it unstable? If so, possibly a high side mosfet is faulty.

[Learn2Day]

Re: Toshiba c660 - NB burns instantly

Solved! I detected a faulty USB port with a shortened pin, replaced it and replaced the NB as advised by spidey (TYSM!!), and the laptop finally boots!
I'm about to re-assemble the laptop and test it extensively. Will post results.

Cheers.

[Learn2Day]

Re: Toshiba c660 - NB burns instantly

Still unsolved!

I found out UC1 (RTS5137) is busted, probably due to USB port short... Will post results after finding a replacement.

Cheers.

[dj_ricoh]

Re: Toshiba c660 - NB burns instantly

Where was the short, what pin was shorted?
Some pics will have been nice :-)

[Learn2Day]

Re: Toshiba c660 - NB burns instantly

Hey guys, this board is becoming an absolute nightmare..

I had replaced already the NB and USB port which made it boot, and after verifying it was turning off after a few seconds I detected UC1 was burning up too...

I finally got it replaced, only to find out although UC1 doesn't burn anymore but the issue is still there..

I'm exhausted and out of ideas.. Do you guys have any tips for me or should i just quit and bin it?

Thanks.

P.S. - Ricoh, the USB port was shorted, don't really know which pins, maybe all.

[dj_ricoh]

Re: Toshiba c660 - NB burns instantly

I was wondering what pins was in short so you can know how to check it fast.

[Learn2Day]

Re: Toshiba c660 - NB burns instantly

Well, if we assume it was all or maybe just the middle ones, what would you recommend me to check?

Thanks.

[mohamed.mostafa]

Re: Toshiba c660 - NB burns instantly

chk usb power control "RT"
REPLACE CPU VCORE CONTROL "isl62283"
REMOVE SOUND CHIP "ALC259"

[Learn2Day]

Re: Toshiba c660 - NB burns instantly

Hi Mohamed,

I'm having a hard time locating usb power control RT, could you help a little more?

Thanks.