Toshiba A300-20N restarting like bad cpu

[Prosatanosz]

Hi!

This unit if switched on, then shut off after 1-10 sec. And again, again, try to start. Token replaced, cpu replaced. Widthout vga card stay on, but of course no picture. Another vga card the same. MB problem, not token, not cpu, not vga card. Voltages seems ok. Any idea?

Thx

[SMDFlea]

Re: Toshiba A300-20N restarting like bad cpu

Have you flashed the bios.

[mielta]

Re: Toshiba A300-20N restarting like bad cpu

Hi
Check with an Bench PSU how many amp
i think one powersuplly is not stable

[Prosatanosz]

Re: Toshiba A300-20N restarting like bad cpu

Bios replaced from other board. Still the same. There is only 2 psu switching on/off + cpu psu. Caps replaced. No luck.

[tomodachi]

Re: Toshiba A300-20N restarting like bad cpu

Does it display logo or any picture before restart ?
if yes, your choice of capacitors might be poor, insufficient or misplaced.
u probably took your new capacitors from scrap boards, and there is a very small chance that they lost their capacitance.

[Prosatanosz]

Re: Toshiba A300-20N restarting like bad cpu

No picture, at all nothing. Power on led comes on, then off repeatedly.

[Stevie2001]

Re: Toshiba A300-20N restarting like bad cpu

Put original bios in.
This is power fault

[tomodachi]

Re: Toshiba A300-20N restarting like bad cpu

Seek for liquid damage, especially under wristbar and touchpad zone, previous repair attempsts could also make that happen.
And what is the amps draw during restart ?

[Prosatanosz]

Re: Toshiba A300-20N restarting like bad cpu

No damage, no liquid, no previous repair. Current draw cant measure, sorry. Without vga card stay on. No idea. All power seems to be ok.

[tomodachi]

Re: Toshiba A300-20N restarting like bad cpu

Then there should be a dead short on VGA card, please measure the graphics chip supply ohms to ground