Asus PC3-E Intermittently Rebooting

[rebmo]

I have built the following system

Asus P3C-E Mobo, P3-700mhz Slot 1 100mhz fsb, 128mb PC100 SDRAM on Asus adapter for RDRAM slot,Enlight 300w PS ATX Case, 8.4mb ATA33 HDD, 2mb Trident PCI Video card, SB16 PCI Sound Card, 3com 10/100 NIC, 3Com modem.

The problem: The system seems to run fine other than the fact that it reboots intermittently all on it's own. Occasionally, when I try to install from the CDROM it reboots, but there is no repeatable pattern. All hardware with the exception of the Motherboard and processor has been swapped out. The power supply/has been used for about a year with no problem in a similar load situation.

Seems I have heard of people with this intermittent reboot problem.
Does anyone have any suggestions on what might be causing these reboots?

Appreciate any advice from Asus P3C-E builders, or anyone having solved a similar problem.

[Toaster]

Howdy,
There are some CDROM drives which have problems switching between real and enhanced mode drivers. They sometimes reset the IDE bus which often results in instabilities or random reboots.
Try a different CDROM drive from another maker. Delete any mention of CDROM device drivers in your autoexec.bat and config.sys files if you do not need support at a DOS prompt.
Connect the CDROM on its own channel as some CDROMs attempt to "master" the bus when another device will not relinquish the bus.

[rebmo]

Thanks for the suggestions on the CDROMs

I replaced the current IBM 4x CDROM with 2 known good CDROMS to confirm it is not the CDROM at fault. One was a the new in Iomagic 48x and the other was an AOPEN 55X. Both were from good operating PCs. Still the same problem. The thing that causes reboot the most frequently is accessing web pages. I am using a NIC card to get to my cable router. The PC does also reboot all on it's own less frequently at random intervals. the CDROM was a good suggestion, any other thoughts?

Has anyone built a system with the Ausus P3C-E Motherboard with the SDRAM Adapter and had success?

Thanks Again, Rebmo

[archie]

If you tap lightly on the case, does it reboot? I recall an instance when a computer would reboot on it's own. Tapping on the power supply would make this happen also. I ended up putting everything in another case. Much later, in trying the original case with its power supply for a different setup, I found that everything was fine ... leading to the conclusion that there was some type of grounding issue or contact problem somewhere ... possibly a problem between the mobo and case.

[rebmo]

I actually had already tried tapping on the power supply and the case and lightly working some of the connections and cables. None of this has caused the reboot. I did try a install of winXP and it could not complete installation due to reboots. Did get a blue screen WXP error "Beginning dump of physical memory", however this may not have anything to do with the problem.
I may have to try a different case and Power Supply as agonizing as that will be at this point. Thanks for your advice.

Reb

[Cricket]

Hi rebmo,

I've never heard of SDRAM to RDRAM adapters before. When you use the adapter, do you have to change a setting in BIOS or a jumper on the motherboard so the system knows which type of RAM is being used?

Do you think you can get ahold of a pair of RDRAM sticks to try out?

Cricket

[rebmo]

Cricket,

The memory adaptor is supplied by Asus. At the time the P3C-E motherboards were made the Rambus RDRAM was in the $800 range for 128mb so the SDRAM adapter was designed in as an option. The bios automatically switches to SDRAM Sensing when the adapter is used. The bios recognizes the 100mhz SDRAM and sets up the FSB frequency correctly at 100mhz for the 700mhz processor. 7X multiple. I am working with a friend to get him to pull his RDRAM but I can't get to it till this weekend (good suggestion). I have never dealt with an adapter as mentioned previously, so I am leery, but it is designed by Asus and bios supported.

Rebmo

[glc]

Get rid of the adapters and put RDRAM in it. There was a huge issue with that.

[rebmo]

I recieved a few messages on different newsgroups/forums all suggesting that the SDRAM adapter was the problem. I had great hopes for this potential solution, so I went a borrowed 2x256mb RDRAM from a known good machine, plugged it, and same problem. Checked out the bios and it set up fine for the RDRAM, tried ECC on and off, still intermittent reboots.

I did patiently re-install WXP and it ran fairly well with only one reboot, but also locked up on occasion when surfing the web on cable hub to NIC. The only thing I have not done is swap out the power supply (although the 300W PS/Case was taken from a reliable P2-350 machine), processor, and motherboard. I, unfortunately, have another P3C-E motherboard. and another enlight 300w case, Also a P3-886 processor on the way. I am going to swap those parts, or build a parallel system next. Unless anyone has any more suggestions, I have a lot of work to do. I'll let you know what I end up with.

Thanks for the suggestions, they all seemed logical.
BTW, does anyone know if the SDRAM adapters ever did work for the P3C-E?

Thanks, Reb

[glc]

Do you have CRIMM's in the empty slots?

[rebmo]

Yes, there are two slots, in one I have the CRIMm in the one desinated slot and the SDRAM Riser in the other designated slot.

Reb

[rebmo]

Well, here's the fix.

I happened to have ordered 2 Asus P3C-E motherboards for 2 budget systems I am building, and finally got down to swapping out the motherboard. Machine works fine now. I am running a P3-700MHz, 100mhz FSB with 1 stick of 128mb SDRAM in the memory adapter. I loaded Windows XP Pro and it runs like a champ. The other most likely defective motherboard and memory adapter are going back to the supplier for an RMA exchange. I'll let the group know if I come up with an 2nd good mobo.

Thanks for all the ideas for troubleshooting,

Reb