Acer 8930g random reboot

[GeorgeBlitz]

32-bit Debian boots, runs great. It'll run for days on Debian.

Minimal system: mobo has PCIe cards pulled off. Just ssd, ram, keyboard, and display.

Any other OS, or even 64-bit Debian, starts to boot, then reboots the laptop just as the drivers load. It's not a specific driver that causes the reboot: sometimes one, sometimes another, but it is guaranteed to reboot before all the drivers are loaded. DRAM swap doesn't change it. CPU swap doesn't change it. And, I don't have a donor nVidia board.

BIOS doesn't provide for disabling SpeedStep.

No liquid damage. No heat issues. Swapped the 220uf tantalums because capacitors are evil and I have 4 whole tubes of these things. Plus my flux bottle was overfull.

The behavior implies a speedstep issue. I have confirmed that the 32-bit Debian does not enable SpeedStep by default. But that sounds like an unacceptably deep rabbit hole.

Ideas? Which capacitor causes this flakey behavior? Cuz it's always a cap.

[guzica]

Re: Acer 8930g random reboot

Hi, replace NEC Tokin with 4x330uF.

[GeorgeBlitz]

Re: Acer 8930g random reboot

Hi, replace NEC Tokin with 4x330uF.

Good plan! I'll order some Panasonics. That's a solid 3 days I won't have to stare at this board!

I'll post back in 3-5 days.

Thanks!

[GeorgeBlitz]

Re: Acer 8930g random reboot

I tested those caps. Yup! Two of them are dodgy. 990K on one of them. Initial ESR is supposed to be 4M ohm.

This might not be THE problem, but it is definitely A problem.

For the sake of future folk, I'm going to replace the four 330uf 2.5V caps under the NEC / Tokin 0E907 plastic lid with four Panasonic 2R5TPE330M7 caps. I'll put the NEC / TOKIN cover back on as it likely eases the thermal shock that these caps endure when power is removed.

Excellent call, guzica. Thanks again.

[GeorgeBlitz]

Re: Acer 8930g random reboot

I was skeptical, but yep, that fixed it. Thanks yet again.