satellite l450d Water damaged

[gcomputers]

Hi i have this toshiba i got from a costumer that hi say is water damaged.

I checked the board and i don t see any damage.
PU4 have 19 v arround it but i find i problem
Arround PU5 (page 38) on PQ19 PL5 PC57 i don t have 5V.
another problem is PQ18 pin 1,2,3,5,6,7,8 , PQ56 , Q14 pin 1,2,3,5,6,7,8 are shorted with ground .

So i changed PQ16, PQ19, PQ18, Q14, PU5 taked from functionaly mainboard .

ANY IDEA PLEASE????????

[gcomputers]

Re: satellite l450d Water damaged

Any suggestion please?

[dspok]

Re: satellite l450d Water damaged

Check all the short if it is still on board.

[gcomputers]

Re: satellite l450d Water damaged

that shorted points are still on board

[dj_ricoh]

Re: satellite l450d Water damaged

that shorted points are still on board

i`m charging a tablet battery today and try in this weekend.

3.7v 3700mAH

i will blow up a few.

Q: freeze spray or ipa in a spray bottle?

[gcomputers]

Re: satellite l450d Water damaged

Thanks for the reply , yes i cleaned it with IPA
today i changed PU5 again ,
and connect 5v from external usb power to pin 7.8 of pq19 nothing happened only PU5 heats up too much. on this pin need to have 5v but no voltage.

[atsio]

Re: satellite l450d Water damaged

Clear the solder from PJ1 and PJ5 and check resistance from both sides

[gcomputers]

Re: satellite l450d Water damaged

Thanks ATSIO , cleaned PJ1 and PJ5 and the resistance on booth side is 23ohm,
what do you think?
With PJ1 cleaned the short goes from PQ18 , PC56 no short,
and Q14 pin 1,2,3,5,6,7,8 are shorted with ground.
Thanks again

[atsio]

Re: satellite l450d Water damaged

When you clean the pj's from solder you can see that they are two pad for each pj. One pad (for pj1) is from the line 3valwp and the other to line 3valw. The same for pj5 (5valw and 5valwp). Check the resistance on each pad (all four) relative to ground. Also determine which pad is which buy checking for continuity with pl4 (3valwp) and pl5 (5valwp).

[atsio]

Re: satellite l450d Water damaged

Also remove q14 and check for resistance relative to ground on pins 1 and 8.

[gcomputers]

Re: satellite l450d Water damaged

3valwp o ohm 3valw 10 mohm
5valwp o ohm 5valw 8,3 ohm

q14 pin 1 = 0.1ohm pin 8 = 0.1 0.2 ohm
also i just changed pu7
but i see another problem pu5 maked too hot.

[atsio]

Re: satellite l450d Water damaged

You can't have 10 mohm on 3valw pad (pj1) and 0.1ohm on pins 1 and 8 of q14, check again.
Solder a wire on one of the pads of pr38 and use your lab supply to apply current to the board. Be careful and apply slowly current and do not exceed 0,5 amps. If the board draws current check what is getting hot.

[gcomputers]

Re: satellite l450d Water damaged

sorry you are right
3valw o ohm 3valwp 10 mohm

[atsio]

Re: satellite l450d Water damaged

3valw 0 ohm or infinite on your mutlimeter

[gcomputers]

Re: satellite l450d Water damaged

case closed pu5 burned and on the pads 7.8 damaged so nothing to do.........
Thanks again Atsio for your time