toshiba C855 PLF/PLR/CSF/CSR rev2.1 no power

[rookieme]

Hi, I need some assistance with a Toshiba C855.
It seems that the Vbat voltage is only 1V.
I've suspected the PQ24725 and replaced it but with no luck.

PQ24725 has the following voltages
pin1 0,9V
pin2 0,9V
pin3 0,9V
pin4 0,9V
pin5 1,42V
pin6 2,4V
pin7 0,14V
pin8 0,9V
pin9 0,9V
pin10 0,5V
pin11 0,9V
pin12 1V
pin13 1V
pin14 0V
pin15 0V
pin16 5,9V
pin17 5,8V
pin18 1V
pin19 1V
pin20 18,5V


The schematic is not the same but seems to be similar at the charger circuit.
Any help is appreciated

[meritosari]

Re: toshiba C855 PLF/PLR/CSF/CSR rev2.1 no power

did you check these mosfets? if any shorted one or both of them

[ridamouh159]

Re: toshiba C855 PLF/PLR/CSF/CSR rev2.1 no power

WHAT IS THE OUT VOLT OF FDS8884
I HAVE a mother als your in the same probleme
a have changing this mosfet

[rookieme]

Re: toshiba C855 PLF/PLR/CSF/CSR rev2.1 no power

did you check these mosfets? if any shorted one or both of them

The two mosfets were the first I checked so I guess that their driver BQ was the fault.

[dj_ricoh]

Re: toshiba C855 PLF/PLR/CSF/CSR rev2.1 no power

that fds got low V on gate .
the think is i think its shorted.
i replace only that crap and it work for every c800 series

weird tough.

maybe yours its new for me

[rookieme]

Re: toshiba C855 PLF/PLR/CSF/CSR rev2.1 no power

I'll remove it and measure it again.

[dj_ricoh]

Re: toshiba C855 PLF/PLR/CSF/CSR rev2.1 no power

Something with the gate.
It shows up normal. Test ok with diode mode.

But for some.reasson gate is low

[rookieme]

Re: toshiba C855 PLF/PLR/CSF/CSR rev2.1 no power

It finally worked.
The second mosfet, a tiny one was shorted.
It seems I wasn't able to touch it's feet properly to measure it at first.
It is a si7326 and I replaced it with a si7716 which has higher amber value.
Thank you all.

[KEVSPIT]

Re: toshiba C855 PLF/PLR/CSF/CSR rev2.1 no power

Well done rookieme

[dj_ricoh]

Re: toshiba C855 PLF/PLR/CSF/CSR rev2.1 no power

Hehehe cudos with fix.

A new day another save from scrap pile.
I love a good happy ending.