Computer resets several times while booting

Garry Knight

For some time now my machine has been resetting itself several times at boot
time before eventually booting successfully. After some investigation I'm
still no closer to finding the cause of the problem. Apologies for the
length of this post but I want to make sure I give enough information about
what I have and haven't tried in my attempts to fix it.

I've run memtest overnight with good results. I've also pulled all of the
RAM chips and tried booting with just one 256 MB module at a time and it
still resets. This leads me to believe that it's not the RAM that's at
fault. At least, unless all three modules became faulty at the same time,
which I feel is unlikely. I've also pulled all of the PCI cards and the
problem remains.

The machine was running fine for a few years under various Mandrake/Mandriva
Linux versions and then suddenly started resetting whenever the sound card
was used, though not every time. It would happen when playing MP3s or video
files, but not when playing CDs. The sound card is a SoundBlaster 128 PCI
and there's also an on-board SoundBlaster-compatible module which is
disabled in the BIOS. As I say, I've taken the sound card out and the
rebooting problem remains, with or without the on-board sound enabled.

Then it started rebooting while Mandriva was initialising. And it was doing
so at different times during the initialising process, sometimes rebooting
when (or soon after) udev initialised, sometimes later than this, and
sometimes not until I'd logged in and the KDE desktop had appeared.
Nowadays it first reboots when udev initialises, which led me to believe it
might be a problem with the PCI cards or the drives.

If I leave the machine to keep rebooting it will, after about 6 or 7 reboots
at later stages during the Linux boot process, eventually get to the log-in
prompt, and if I leave it a little while after that I can successfully log
in and everything will be OK until the next time I power up. If the machine
has been on for a couple of hours I can reboot without any problems. It's
almost as if the box needs to "warm up" in order to get all the way through
the boot process. Oh, and the first thing I checked was the processor fan,
which is working fine.

It resets while booting Mandriva 2007 Free, it resets while booting Ubuntu
6.1 (no longer on the machine), it resets while booting from the Mandriva
One 2008 CD and a Knoppix 5.0 CD, and it resets while attempting to boot
the newly-installed Mandriva One 2008.

I've come to the conclusion that the problem isn't distro-specific, it isn't
caused by failing RAM chips, and it isn't caused by the sound-card (though
it looked at one time as if it was). It seems to me that there's a
possibility that it's caused by a faulty hard disk, though that seems
unlikely as it reboots at different times during the boot process. I had
wondered whether there might be a problem with IRQ collisions, but the fact
that the problem still occurs after all of the PCI cards have been pulled
makes me doubt this. There might be a problem with the motherboard, but
I've no way of testing that. And since the machine resets at various times
during the boot process, inspecting /var/log/boot.log and /var/log/messages
tells me nothing useful.

In fact, I've just about come to the end of my somewhat limited knowledge of
a) hardware, and b) the Linux boot process, so I need help from you guys.
Or a new PC...

The box is a generic Chinese box with a Pentium 1.2 GHz processor and the
full quota of 768 MB of RAM. It has a Matrox G400 graphics card in the AGP
slot. It has an on-board sound card and soft modem, both disabled. The
primary hard disk is a 40 GB Seagate ST340823A.

I've included below all of the BIOS settings just in case I've managed to
***** up the settings somehow, though the only changes I've made during the
testing process is to select the Failsafe settings, then the Optimized
settings, neither of which made any difference to the rebooting problem.

I'm out of ideas and I'd be grateful for any help on this one. Please let me
know if you need any other information.


BIOS SETTINGS
=============

Standard CMOS Features
----------------------
IDE Primary Master ST340823A
IDE Primary Master Auto
Access Mode Auto
Capacity 40022 MB
Cylinder 19158
Head 16
Precomp 0
Landing Zone 19157
Sector 255
IDE Primary Slave ST340014A
IDE Primary Slave Auto
Access Mode Auto
Capacity 40022 MB
Cylinder 19158
Head 16
Precomp 0
Landing Zone 19157
Sector 255
IDE Secondary Master LITE-ON DVDRW SHW-163]
IDE Secondary Master Auto
Access Mode LBA
Capacity 0 MB
Cylinder 0
Head 0
Precomp 0
Landing Zone 0
Sector 0
IDE Secondary Slave SAMSUNG DVD-ROM SD-61
IDE Secondary Drive Auto
Access Mode Auto
Capacity 0 MB
Cylinder 0
Head 0
Precomp 0
Landing Zone 0
Sector 0
Drive A 1.44M, 3.5 in.
Drive B None
Video EGA/VGA
Halt On All , But Keyboard
Base Memory 640K
Extended Memory 785408K
Total Memory 786432K

Advanced BIOS Features
----------------------
Virus Warning Disabled
CPU Internal Cache Enabled
External Cache Enabled
CPU L2 Cache ECC Checking Enabled
Quick Power On Self Test Enabled
First Boot Device CDROM
Second Boot Device HDD-0
Third Boot Device Floppy
Boot Other Device Enabled
Swap Floppy Drive Disabled
Boot Up Floppy Seek Enabled
Boot Up NumLock Status On
Gate A20 Option Fast
Typematic Rate Setting Disabled
x Typematic Rate (Chars/Sec) 6
x Typematic Delay (MSec) 250
Security Option Setup
OS Selector For DRAM > 65 MB Non-OS2
Video Bios Shadow Enabled
C8000-CBFFF Shadow Disabled
CC000-CFFFF Shadow Disabled
D0000-D3FFF Shadow Disabled
D4000-D7FFF Shadow Disabled
D8000-DBFFF Shadow Disabled
DC000-DFFFF Shadow Disabled

Advanced Chipset Features
-------------------------
DRAM Clock 100M
SDRAM Cycle Length 3
Bank Interleave Disabled
Memory Hole Disabled
PCI Master Pipeline Req Enabled
P2C/C2P Concurrency Disabled
Fast R-W Turn Around Disabled
System BIOS Cacheable Disabled
Video RAM Cacheable Disabled
Frame Buffer Size 32M
AGP Aperture Size 128M
AGP Mode 4X
AGP Driving Control Auto
x AGP Driving Value DA
OnChip USB Enabled
USB Keyboard Support Enabled
OnChip Sound Disabled
OnChip Modem Disabled
CPU to PCI Write Buffer Enabled
PCI Dynamic Bursting Enabled
PCI Master 0 WS Write Enabled
PCI Delay Transaction Disabled
PCI#2 Access #1 Retry Enabled
AGP Master 1 WS Write Disabled
AGP Master 1 WS Read Disabled

Integrated Peripherals
----------------------
OnChip IDE Channel0 Enabled
OnChip IDE Channel1 Enabled
IDE Prefetch Mode Disabled
Primary Master PIO Auto
Pimary Slave PIO Auto
Secondary Master PIO Auto
Secondary Slave PIO Auto
Pimary Master UDMA Auto
Pimary Slave UDMA Auto
Secondary Master UDMA Auto
Secondary Slave UDMA Auto
Init Display First PCI Slot
IDE HDD Block Mode Disabled
Onboard FDD Controller Enabled
Onboard Serial Port 1 Auto
Onboard Serial Port 2 Auto
UART 2 Mode Standard
x IR Function Duplex Half
x TX,RX inverting enable No, Yes
Onboard Parallel Port 378/IRQ7
Onboard Parallel Mode EPP
x ECP Mode Use DMA 3
Parallel Port EPP Type EPP1.9
Onboard Legacy Audio Enabled
Sound Blaster Disabled
SB I/O Base Address 220H
SB IRQ Select IRQ5
SB DMA Select DMA1
MPU-401 Disabled
MPU-401 I/O Address 330-333H
Game Port (200-207H) Enabled

Power Management Setup
----------------------
ACPI function Enabled
Power Management
Power Management User Define
HDD Power Down Disable
Doze Mode Disable
Suspend Mode Disable
PM Control by APM Yes
Video Off Option Suspend -> Off
Video Off Method V/H SYNC+Blank
MODEM Use IRQ 3
Soft-Off by PWRBTN Instant-Off
State After Power Failure Off
Wake Up Events
VGA Off
LPT & COM LPT/COM
HDD & FD On
PCI Master Off
PowerOn by PCI Card Disabled
Modem Ring Resume Disabled
RTC Alarm Resume Disabled
x Date (of Month) 0
x Resume Time (hh:mm:ss) 0:0:0
Primary INTR On
IRQs Activity Monitoring
IRQ3 (COM 2) Enabled
IRQ4 (COM 1) Enabled
IRQ5 (LPT 2) Enabled
IRQ6 (Floppy Disk) Enabled
IRQ7 (LPT 1) Enabled
IRQ8 (RTC Alarm) Disabled
IRQ9 (IRQ2 Redir) Disabled
IRQ10 (Reserved) Disabled
IRQ11 (Reserved) Disabled
IRQ12 (PS/2 Mouse) Enabled
IRQ13 (Coprocessor) Enabled
IRQ14 (Hard Disk) Enabled
IRQ15 (Reserved) Disabled

PnP/PCI Configurations
----------------------
PNP OS Installed No
Reset Configuation Data Disabled
Resources Controlled By Auto(ESCD)
x IRQ Resources
x DMA Resources
PCI/VGA Palette Snoop Disabled
Assign IRQ For VGA Enabled
Assign IRQ For USB Enabled

PC Health Status
----------------
Current CPUFAN1 Speed 4818 RPM
Current CPUFAN2 Speed 0 RPM
Vcore 1.82 V
3.3V 3.27 V
5V 4.73 V
12V 12.78 V

Frequency/Voltage Control
-------------------------
Auto Detect DIMM/PCI CLk Enabled
CPU Host Clock (CPU/PCI) Default

--
Garry Knight