Hi! An urgent help is needed for Toshiba A205-S5825 regular shut down issue.

Steps already taken :

1-cleaned fan system (was a little dusty but not clogged), removed dried paste and applied new one to CPU and GPU.

2-Tried naked mobo with a working ram, CPU, KB and Lcd display, enter bios screen, lap always shut down after about 1'50s.

3- Scanned mobo with an infra-red thermometer, Max temperature registred 42° at SB, so no heat issue.

4- Checked Thermal Sensor ADM1032ARM :
VDD : 3Vs
D+ 2.38V
D- 0v
EC_SMB_CK2 and _DA2 : 5.6V each
pin 4 "Therm#" and 6 "Alert#" not connected.

Please note that CPU of A205-S5825 series doesn't use big "Nec-Tokin cap" but 330uf small caps.

Also Tried with Mobo +ram +fan but without CPU it also shut down at about same time.

Has any one dealt with the same issue, or any clue as where to dig further

Thank you

22 had already viewed my post, but no reply.
Still waiting for any suggestion from colleagues. Hope not to be disappointed.

1 st step try change bios firmware
2 - try change your charger
3 - may be you have a cracked USB port on mainboard

1-Updating bios might be risky, as lap is shutting down after 1'50s (see my 1st post). Would it be possible within this short time ?
2- Changing charger is among 1st things I did to no avail.
3- Checked no visual crack and no short at usb ports.

Any new suggestion or comment is welcome.

Thank you.