Toshiba A300-1EC PSAG0E Strange Problem

[ahmetozay]

Dear Friends, i have this toshiba a300, before it was not responding to the switch, i came accross that the bios battery has flooded and shorted. so i changed it with the new one. Then motherboard stared and worked couple of hours i closed the laptop. In the morning i tried to open it but again no respond to the switch so i flashed the bios with xeltek pro 500s with the lastest rev from toshiba website. the unit came alive again no problem hours of working but when you shut it down again no respond to the switch. everytime i have to program the bios. Everything seems ok . But why the bios erase itself and i have to reprogram it again and again. Any advice would be very apreciated. Thanks and regards

[lefos]

Re: Toshiba A300-1EC PSAG0E Strange Problem

Does this one have a nec tokin ? Look for a big capacitor behind the cpu slot.

[tomodachi]

Re: Toshiba A300-1EC PSAG0E Strange Problem

you can try to replace BIOS chip, it might be gone

[Microbe]

Re: Toshiba A300-1EC PSAG0E Strange Problem

YOU CAN VERIFY CHIP PROGRAM BEFORE REPROGRAM IT TO KNOW IF IT'S THE BIOS OR NOT.
IF SO JUST REPLACE THE BIOS CHIP AS tomodachi SAID.

AND IF THE PROGRAM VERIFIED SUCCESSFULLY THEN IT HAS TO BE THE "TOKIN CAPACITOR" BEHIND CPU AS LEFOS SAID.

[mrsuave001]

Re: Toshiba A300-1EC PSAG0E Strange Problem

when i replace e907 l300 toshiba the unit won't boot only power and the voltage across e907 is 4volts is it ok pls help

[rievax_60]

Re: Toshiba A300-1EC PSAG0E Strange Problem

when i replace e907 l300 toshiba the unit won't boot only power and the voltage across e907 is 4volts is it ok pls help

4v would be too high, are you certain? Show us a photo and tell us what parts are used.

[mrsuave001]

Re: Toshiba A300-1EC PSAG0E Strange Problem

it's almost 4volts across e907 when i replace e 907

[mrsuave001]

Re: Toshiba A300-1EC PSAG0E Strange Problem

what should be the voltage across e907 and what circuit does e907 get. its supply

[mrsuave001]

Re: Toshiba A300-1EC PSAG0E Strange Problem

by the before i replace e907 i tried to power it without e907 pls help

[rievax_60]

Re: Toshiba A300-1EC PSAG0E Strange Problem

The NEC Tokin OE907 capacitor filters the Vcore voltage to the CPU. Its usually 0.8v to 1.2v.
I really dont think it is possible to have a sustained 4v on the Vcore.

[mrsuave001]

Re: Toshiba A300-1EC PSAG0E Strange Problem

that's why i need help how to work on it any solution how to repair it e907 is new i replace it already

[rievax_60]

Re: Toshiba A300-1EC PSAG0E Strange Problem

This thread covers the topic, https://www.badcaps.net/forum/showthread.php?t=8991
It is a long thread now.

[mrsuave001]

Re: Toshiba A300-1EC PSAG0E Strange Problem

thank you for responding

[viji90]

Re: Toshiba A300-1EC PSAG0E Strange Problem

hai i need toshiba sattelite A300-1EC bios bin

[ganeshcell]

Re: Toshiba A300-1EC PSAG0E Strange Problem

is your rtc section ok?
when not turning on chech 32.768mzh at rtc crystal
As u told bios battery was shorten
this may leed to rtc failure