toshiba satellite c855d-s5320 need help

[Romy2018]

Hi i need help to fix this Toshiba satellite c855d-s5320 board id:6050a2509701-MB-A03. i checked the voltages 19v is present but there is no 3.3v and 5v. also there is no 3.3v on power switch and no 3.3v on bios chip. can you help me experts here how to fix this please. I am not a novice tech im still in the process of learning repairing boards and new to this forum. can you help me guide to fix this please

[jasko_jacker]

Re: toshiba satellite c855d-s5320 need help

I don't know this board, but usually if the battery charge chip work well (if there isn't a short the battery is in charge status and the led is on) check the +3v and 5v alw chip . post the schematic

[SMDFlea]

Re: toshiba satellite c855d-s5320 need help

I think this is the right schematic, or a close match.

[Romy2018]

Re: toshiba satellite c855d-s5320 need help

Thanks for the response friends. based on schematic of smdflea i checked U6100 TPS51123 is defective, so i replaced with equivalent RT8223M, now there is 3.3v and 5v but there is short on 19v now,and i found that 330uf 6.3v capacitor positive side is shorted to ground, ill tried replacing with tantalum 330uf 6.3v but still the same issue possitive side is shorted to ground but when i removed the capacitor the possitive side is not shorted to ground and plugged charger lights goes present.can anyone help me on this please

[Romy2018]

Re: toshiba satellite c855d-s5320 need help

need help please

[SMDFlea]

Re: toshiba satellite c855d-s5320 need help

Which capacitor is it ?

[Romy2018]

Re: toshiba satellite c855d-s5320 need help

the capacitor shorted to ground is C6100

[SMDFlea]

Re: toshiba satellite c855d-s5320 need help

If C6100 was a ceramic cap replace it with a ceramic cap. I don`t see why the short would go away after removing the replacement cap,then the short is back with the cap in place, unless the replacement cap is also shorted ,or your measurements are wrong. The + side should be 3.3V .

[Romy2018]

Re: toshiba satellite c855d-s5320 need help

I replaced the cap with tantalum 330uf 6.3v if i put the cap +side of cap is shorted to ground but if i removed the cap the +side not shorted to ground and it measured 8.8v on the + side.

[mcplslg123]

Re: toshiba satellite c855d-s5320 need help

Q6100 OR Q6101 might be shorted. Since removing the cap removes the short and when powered it gets shorted means you have short somewhere in 3v line.

[SMDFlea]

Re: toshiba satellite c855d-s5320 need help

EDIT: didn`t see above post by @mcplslg123 .

[Romy2018]

Re: toshiba satellite c855d-s5320 need help

you are right mcplslg123 Q6100 is short but i already replaced it still the same issue cap shorted to ground. but when i removed the cap and plugged the charger orange light is present

[Romy2018]

Re: toshiba satellite c855d-s5320 need help

i checked Q6101 source side pin 123 shorted to ground