Toshiba Satellite A300 NO LED/NO POWER

[marcellodj]

Hello,
the baby on my bench is completely DEAD; no charge led, no power led .. nothing.

Did some preliminary measurements and found that there is no +3V at power switch button; any advice to start for.

Thanks.

[b700029]

Re: Toshiba Satellite A300 NO LED/NO POWER

What is the exact model (so I can try to find a schematic)? The A300 has gone through several revisions and different OEMs.

You should start tracing power starting at DCIN.

[Peter9DO]

Re: Toshiba Satellite A300 NO LED/NO POWER

I'm picking up an Acer with a similar issue, I purchased a DC input in the event that can be the problem, but I'm very doubtful. Good luck my friend!

[marcellodj]

Re: Toshiba Satellite A300 NO LED/NO POWER

Good morning mainbd pn is V000125930, has mxm svga graphic.
Thanks for help.

[b700029]

Re: Toshiba Satellite A300 NO LED/NO POWER

I believe that would be an Inventec PT10G.

Schematic:

Pages 4-12 are the power circuitry. Start tracing from VADPTR on page 5.

[marcellodj]

Re: Toshiba Satellite A300 NO LED/NO POWER

Thanks, customer want a new mobo (is crazy), so i ll try fix the faulty later in my spare time, thanks you b700029 for your help.

[Peter9DO]

Re: Toshiba Satellite A300 NO LED/NO POWER

b700029, where do you get your mobo schematics from?

[b700029]

Re: Toshiba Satellite A300 NO LED/NO POWER

Google

[LudonjaST]

Re: Toshiba Satellite A300 NO LED/NO POWER

To not open a new post Im going to continue here.
I have simmilar problem with my A300D. Have Toshiba A300D AMD motherboard 31BD3MB00F0 A000036910.
First I had problem with gpu generating bad picture (artefacts) and I succeed to fix it with hot air. Than I got annoying message "system configuration data read error" and everything was working fine after press F1 button. So I tried to fix it refluxing southbrige but no succees. After southbrige and gpu I done the same with northbrige.
After that no more blue lights on left, only orange one is lighting and vent just does few steps for a second and stops.
Somebody have some constructive idea??
Thanks to all in advance!

[mscmelo]

Re: Toshiba Satellite A300 NO LED/NO POWER

Hi there. I have the same problem on my A300. With battery charged works fine. With charger connected doesn´t charge the battery and no indication of external power connected. Without battery doesn´t work (no power indication either). Charger works fine (tested on other laptop) and DC jack is fine (with power connected the 19V is present on the jack pins on the mobo). I think the problem is on the power control IC U803 24721C. Did anyone had and resolved this problem ? Thank you.

[Peter9DO]

Re: Toshiba Satellite A300 NO LED/NO POWER

Hi there. I have the same problem on my A300. With battery charged works fine. With charger connected doesn´t charge the battery and no indication of external power connected. Without battery doesn´t work (no power indication either). Charger works fine (tested on other laptop) and DC jack is fine (with power connected the 19V is present on the jack pins on the mobo). I think the problem is on the power control IC U803 24721C. Did anyone had and resolved this problem ? Thank you.

What brought you to that IC?

[mscmelo]

Re: Toshiba Satellite A300 NO LED/NO POWER

Because its the Charge/Power controller so I think can be it...or not. Anyway I´m gonna try measure all diodes, resistors and mosfets around the power and charging circuit and check if there is Vcc on the IC U803.

[arik]

Re: Toshiba Satellite A300 NO LED/NO POWER

Hi everyone, since I have the same issue I guess this is the right place to spill it out
my MOBO is a Satellite A300 , at first I thought the only part I need to replace is the TI - BQ24721C PMIC that was burned (probably by a fake AC Adapter ) so I did, twice... (don't ask) then I replaced the fuse next to the DC Jack , which I assume that burned by a shorting mosfet -> and the 2 shorting AM4825P (P-CH MOSfet's - with FDS 6675bz ), then the SI4800B MOSfet which gave me the same 170 -180 ohm Res in both sides , then the 10mf CAPS near by , and guess what... the board give me the same Poker face... no Power no LED NADA , so you guys are more than welcome (LOL) to help me with this

P.S. after I replaced the fuse and the shorting mosfets I accidently touched the Winbond chip in the other side of the board and it was hot like a 55 Celsius Degrees (there was no other hot chip's in the board ) have no idea why but may he gets much more Voltage than he should ...

[zendalo]

Re: Toshiba Satellite A300 NO LED/NO POWER

Yo Arik!
Did you solved this issue with the motherboard? When no Led and Power on the motherboard what exactly is needed to change to get power on the motherboard?

[zendalo]

Re: Toshiba Satellite A300 NO LED/NO POWER

http://diagservice.ru/images/razbor/...te-a300-14.JPG
Usually which of the components are out when a motherboard no led, no power?
How to measure with multimeter?

[lord]

Re: Toshiba Satellite A300 NO LED/NO POWER

Does anybody have a working link for the schematic?
Board model PT10G 6050A2171501 MB A03.

I have a non existing 5V_ALW_ON, and TPS51125 keeps burning. I found a burned diod D37, but don't know what it is.

[alejandros]

Re: Toshiba Satellite A300 NO LED/NO POWER

Toshiba satellite C850 no led,no power. Is DEAD.
Please helppp. (schematic diagram)
Thanks

[rtra]

Re: Toshiba Satellite A300 NO LED/NO POWER

Hi everyone,

I have here a toshiba a300 pcb: Inventec PT10G (schematic bellow) that have no led, no fan, no power on battery connector, no tension on power btn.

I measured the charger ICbq24271i get the following values:

pin1 CHGEN -> 18.9
pin2 ACDRV -> 5.67
pin3 ACN -> 0.19
pin4 ACP -> 0.19
pin5 ACDET -> 5.67
pin6 BYPASS -> 0
pin7 EAO -> 0
pin8 EAI -> 0
pin9 FBO -> 18.9
pin10 AGND -> 18.9
pin11 VREF5 -> 0.19
pin12 VCC -> 0.19
pin13 SDA -> 0.19
pin14 SCL -> 0.19
pin15 TS -> 0.19
pin16 ISYNSET -> 0.19
pin17 IOUT -> 0.18
pin18 BAT -> 4.17
pin19 SRN -> 0.01
pin20 SRP -> 0.01
pin21 SYNN -> 18.9
pin22 SYNP -> 4.96
pin23 SYS -> 0.01
pin24 BATDRV -> 4.96
pin25 ALARM -> 4.93
pin26 PGND -> 0.01
pin27 LODRV -> 12.48
pin28 REGN -> 1.31
pin29 PH -> 18.9
pin30 HIDRV -> 18.9
pin31 BTST -> 12.37
pin32 PVCC -> 3.1

=========
fuse801 is ok

Can anyone give a hint what to check next?