Toshiba Satellite A300 No Power Problem

[stereotype100]

Hello!

This is my first post here after having read lots of useful information on the site.
I have a complicated problem with my TOSHIBA A300 laptop.
It won't power up, neither with AC adapter nor with battery. No leds on, no signs of life.

Technicians at a local repair-center told me that there may be a short circuit in the Hall Sensor circuit, because an SMD component (PT3661-BB) is missing. (I indicate it with a red arrow on the photo below)

http://i1311.photobucket.com/albums/...ps01df0659.jpg

I also found out that an A6 diode (BAS316) has also been unmounted from the exact same circuit! ( I indicate it with a yellow arrow below)

http://i1311.photobucket.com/albums/...psd1d13d3b.jpg

And this is another photo of the circuit: http://i1311.photobucket.com/albums/...psaf7db66b.jpg

Now, I am using a multimeter to test continuity and resistance in the circuit according to the board Schematics I found and things seem to be ok. Sadly, I have no AC adapter at the moment to test voltage.

I have also tested other circuitry on the board and all seems good,too.
Truth is, I don't know if that's a safe way to detect a short on the mobo..

What should I do now? Can these components be replaced for the machine to work again? I don't believe there is a short circuit, because motherboard was giving signal to external monitor before leaving it at the repair-shop.
There are also no signs of leaked capacitors or bad smell.

Please guide me as to what I should check. If you need any other information (such as the circuitry diagramms) or more photos, just ask me.

Thank you in advance for your time

[stereotype100]

Re: Toshiba Satellite A300 No Power Problem

No one?

[trebo]

Re: Toshiba Satellite A300 No Power Problem

No one?

when I click on your photos, that's all I get is "this page can't be displayed"
if everyone else is getting the same, maybe that's why you havent got any help

[stereotype100]

Re: Toshiba Satellite A300 No Power Problem

when I click on your photos, that's all I get is "this page can't be displayed"
if everyone else is getting the same, maybe that's why you havent got any help

Ok you're right, now i realised it...Sorry,I'll try and fix it

[stereotype100]

Re: Toshiba Satellite A300 No Power Problem

Hello!

This is my first post here after having read lots of useful information on the site.
I have a complicated problem with my TOSHIBA A300 laptop.
It won't power up, neither with AC adapter nor with battery. No leds on, no signs of life.

Technicians at a local repair-center told me that there may be a short circuit in the Hall Sensor circuit, because an SMD component (PT3661-BB) is missing. (I indicate it with a red arrow on the photo below)



I also found out that an A6 diode (BAS316) has also been unmounted from the exact same circuit! ( I indicate it with a yellow arrow below)



And this is another photo of the circuit:


Now, I am using a multimeter to test continuity and resistance in the circuit according to the board Schematics I found and things seem to be ok. Sadly, I have no AC adapter at the moment to test voltage.

I have also tested other circuitry on the board and all seems good,too.
Truth is, I don't know if that's a safe way to detect a short on the mobo..

What should I do now? Can these components be replaced for the machine to work again? I don't believe there is a short circuit, because motherboard was giving signal to external monitor before leaving it at the repair-shop.
There are also no signs of leaked capacitors or bad smell.

Please guide me as to what I should check. If you need any other information (such as the circuitry diagramms) or more photos, just ask me.

Thank you in advance for your time

[spidey]

Re: Toshiba Satellite A300 No Power Problem

Check ACIN and LID_SW#(this may change acording to manufacturer) on EC, using schematic. The parts you show in the pictures are not unmounted, they are just not mounted due to changes of rev. if you think hall sensor circuit is not working you should measure it. But i think you must flash the bios first. Did you check standby voltages ? how about current consumption ?

[stereotype100]

Re: Toshiba Satellite A300 No Power Problem

Thank you for your answer!

No, I didn't check any voltages because I have no AC adapter yet.
Should I check voltages on ACIN and LID_SW? Or is continuity enough?
And how can I flash the bios with no power..?

[dj_ricoh]

Re: Toshiba Satellite A300 No Power Problem

i`m sry but i don`t want to hijack anything i`m working on a dell m5030 amd ver. with no backlight on the led but when i finish it or atleast try i can help you with your toshiba

i got a the half working intel ver a300-1mc but understand that i need to finish mine first.

find the schem and i will pull out the mainboard and we will check it

[stereotype100]

Re: Toshiba Satellite A300 No Power Problem

Thank you!

I will be waiting for your help!

[spidey]

Re: Toshiba Satellite A300 No Power Problem

i`m sry but i don`t want to hijack anything i`m working on a dell m5030 amd ver. with no backlight on the led but when i finish it or atleast try i can help you with your toshiba

i got a the half working intel ver a300-1mc but understand that i need to finish mine first.

find the schem and i will pull out the mainboard and we will check it

it seems you have backlight, since text is clear.

[spidey]

Re: Toshiba Satellite A300 No Power Problem

Thank you for your answer!

No, I didn't check any voltages because I have no AC adapter yet.
Should I check voltages on ACIN and LID_SW? Or is continuity enough?
And how can I flash the bios with no power..?

you will desolder bios chip and flash it with a programmer using right bios.bin file.
if still it doesnt power up, then start measuring standby circuit, ACIN and LID_SW signals also power button... You dont have anything to do with continuity.

[stereotype100]

Re: Toshiba Satellite A300 No Power Problem

Sadly, I don't have the equipment or skills to desolder a chip yet...
Is desoldering necessary for flashing?

[Sparks88]

Re: Toshiba Satellite A300 No Power Problem

Sadly, I don't have the equipment or skills to desolder a chip yet...
Is desoldering necessary for flashing?

if the board wont power up yes it is

[angel-boy]

Re: Toshiba Satellite A300 No Power Problem

i have the same problem with this model , any resolve of the problem?