Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

[massimiliano1970]

Hi everybody, I am Max and live in Italy.
I ask your help to fix a defective TOSHIBA A300-1BU which turns off as soon as I start it using AC/DC adapter. I don't know whether it works well with battery because a friends of mine gifted notebook without this one.
I've read many topics on this forum about Toshiba power issue (related to Nec/Tokin capacitor) but, unfortunatelly, this motherboard doesn't use this capacitor. I found schematic of motherboard here: "http://www.forcomp.cz/soubory/Toshiba-Satellite-A300.pdf".
As you can see in the pictures I've attached here, there are five capacitors 330uF/2.5V (identified with letter from "A" to "E") involved in CPU power circuit control. I think to replace them with new one.

Do you think this will resolve my problem?

Thanks everybody in advance.
max

[Francisco.s]

Re: Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

Does it turns off so quickly, that don`t let you enter into bios?

[massimiliano1970]

Re: Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

Hi Francisco.s, thank you for your reply.
Yes, I can enter the bios, I restored default settings too. The notebook shuts down suddenly within less 1 minute.

[gabik111]

Re: Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

Check temperature of processor / GPU. It may overheating and automatically temp sensor sending informations to shuts down the system. Caps may be bad but if so I don't think you can even turn it on.

[Francisco.s]

Re: Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

Hi Francisco.s, thank you for your reply.
Yes, I can enter the bios, I restored default settings too. The notebook shuts down suddenly within less 1 minute.

We know more aspects about the problem.
Does the fan start spinning?

[massimiliano1970]

Re: Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

Yes, Francisco, the fan starts normally but the notebook stops after 30/40 seconds.
As gabik111 suggested me, i will check temperature of CPU/GPU.

[ilprincipedeimostri]

Re: Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

Hi, I have the same problem with my Toshiba A300.

I can charge the battery when pc is powered off.
And I can start this pc normally with only the battery.

If I try to connect power DC, the A300 goes off after 2 seconds.

If I try to start the pc with power DC without battery, the pc seems to start but only loop without boot.

My pc only starts with battery and I cannot use its with power DC.

I try different DC power unit without nice results.

I can run Bios menu when start with battery: I tried all different configuration but without good results.

On motherboard I can't see any broken parts (fuses or caps).

Can someone help me?

[rievax_60]

Re: Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

Hi, I have the same problem with my Toshiba A300.

I can charge the battery when pc is powered off.
And I can start this pc normally with only the battery.

If I try to connect power DC, the A300 goes off after 2 seconds.

If I try to start the pc with power DC without battery, the pc seems to start but only loop without boot.

My pc only starts with battery and I cannot use its with power DC.

I try different DC power unit without nice results.

I can run Bios menu when start with battery: I tried all different configuration but without good results.

On motherboard I can't see any broken parts (fuses or caps).

Can someone help me?

Some A200 owners used to disable the CPU drivers as a temporary fix.
Can be found in Device Manager under Processors, in Safe Mode.
It might give us a useful clue.

[welhim]

Re: Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

Hi everybody, I am Max and live in Italy.
I ask your help to fix a defective TOSHIBA A300-1BU which turns off as soon as I start it using AC/DC adapter. I don't know whether it works well with battery because a friends of mine gifted notebook without this one.
I've read many topics on this forum about Toshiba power issue (related to Nec/Tokin capacitor) but, unfortunatelly, this motherboard doesn't use this capacitor. I found schematic of motherboard here: "http://www.forcomp.cz/soubory/Toshiba-Satellite-A300.pdf".
As you can see in the pictures I've attached here, there are five capacitors 330uF/2.5V (identified with letter from "A" to "E") involved in CPU power circuit control. I think to replace them with new one.

Do you think this will resolve my problem?

Thanks everybody in advance.
max

try add the blank slot with 330 caps..feedback me what happen...'' low power on processor ''

[gaper]

Re: Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

I have the same problem with the A300-24z. Have anyone solved the problem?

[spleenharvester]

Re: Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

I'd be very interested to find out if anyone has ever solved similar issues with these.

With the A200s/A300s/L300s/L350s and such which all have NEC Tokin issues, there are lots of people who have the same symptoms but no NEC Tokin.

Surely the problem must be in the same area?

[angel-boy]

Re: Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

I have a toshiba A300 -146 , mainboard DABL5SMB6E0 REV E , wont start up, plug in adapter, the power led appers, if i plug batery appers that is charging, but when press power button , only with batery , or adapter wont start,

any ideea ?

[atsio]

Re: Toshiba A300-1BU power issue (no Nec/TOKIN capacitor)

What is the voltage on pins 3 and 4 of PQ7 when pressing power button?