Computer Reboots?

[CNCRob]

I was wondering if any one could help me out with a computer problem I've been having. My computer for some reason when Im tring to run a part program; it will stop and reboot it self. It nevers happens in the same spot. Sometimes it will run the program all the way through. Then sometimes it will stop after only a few lines. It happens on various different part programs. I just purchased a new/used computer to fit in a enclosure I purchased. My old computer was a tower model and I needed a lay-down one to fit inside the enclosure. I purchased a computer from a guy that sells used computers and computer parts, that lives just up the street from me. The computer is a Deskpro 1000 mhz celeron processor, Right now it has 512mb of Ram. It only has DOS and the CNC control software installed on the hard drive. My old computer was running the same software and never rebooted, running the same part programs. I have tried every thing I know to try to figure it out. I totally unhooked the CNC and it still happens. I even took the computer from the shop at my parents house and brought it to my house, it still does it so I don't think it is a power problem. I also took the first one i got from him back and he gave me another one ( identical) and it still reboots. I tried about six different sticks of RAM with varying sizes and it still does it. I have tried 3 diffent hard drives ranging in size from 2GB to 8GB still no luck. I also changed the 100watt power supply that came standard in it to a 300watt power supply, still didn't fix it. I have also tried about 4 diffenent keyboards. I have tried adding fans and leaving the case door off to make sure it wasn't over heating and it still crashes. I have also tried 3 diffent video cards. I tried using a older version of the CNC control software I am using, it seemed to help some but it still reboots. I am starting to wondering if it is a compatablity issue between the software and the computer athough I have herd that is very rare with DOS based programs. I have also tried 3 different monitors and different power cords with no luck. I have exausted my brain tring to figure it out. But like I said before ,my old computer (which is a Compaq Presario AMD around 500 mhz I beleive) has no trouble running the same programs. I have the software pretty much set up identical(my old computer and new one). I was wondering if anyone has any ideals, maybe Im just over looking the abvious. I have tried various other things also, im having trouble remembering all the things I have tried. But I will post any that I remember. If any have any suggestions please let me know. Thanks- Robbie

[HayTay]

Robbie,

It sounds like you've eliminated everything except the motherboard. Make sure that the motherboard has a proper ground and is not being improperly grounded. I've encountered two cases prevously, the first was whoever assembled/rebuilt the PC used plastic standoffs for ALL of the mounting holes on the motherboard. The board did not have a good ground reference (a more or less floating ground) and after awhile the computers reference voltages would migrate and it would start doing really weird things like locking up, rebooting, emitting strange sounds through the speakers, random floppy disk/cdrom activity, etc.

The second case (actually had more than 1 instance) was where the motherboard had too many ground points. In one PC it was discovered that a drive mounting screw had fallen out and had lodged between the motherboard and the chassis. The vibration of the PC during normal operation would cause the screw to shift slightly or expand due to heat and basically short out the motherboard causing a reboot. In other instances, again goes back to whoever assembled the PC, it was found that there were too many M/B standoffs. The standoffs were used in places where no standoff was engineered to go. Removed the extra standoff(s) and the PC started acting normal. Unfortunately, I wasn't able to save a few "patients" as the extra grounding components rested against something critical and smoked the board.

Another tip, carefully check all of the data cables going to your peripherals (hard drive, floppy drive, cdrom drive(s), zip drive, tape drive, etc.). Again, I have seen where the person who assembled the PC passed the data cables through an opening in the chassis that was sharp. As a result the insulation was nicked or removed from the data cables. During normal operation the cables would vibrate or undergo heat expansion and ground themselves against the chassis causing a lock-up or spontaneous reboot.

Barring all of that, is the PC flashed with the latest BIOS revision? If it isn't I would recommend doing so. If it is, you may want to try to find the previous version and "downgrade".

[Al_The_Man]

Is it only when you run the CNC program with the drives active etc? Although I see that you say you unhooked the CNC hardware.
I would say if it is warm-boot same as CTL-ALT-DEL then it Maybe a software issue, but if it is a cold-boot as in a power down or reset then, I would suspect a power dip problem.
Did you try using the old hard drive in the new PC?
Al.

[NC Cams]

Replace the power supply.

I had a PC do that as if it had a mind of its own and as a last resort, we threw a P/S at it.

That FIXED IT and it never randomly rebooted again.

[HayTay]

Originally Posted by NC Cams Replace the power supply. I had a PC do that as if it had a mind of its own and as a last resort, we threw a P/S at it. That FIXED IT and it never randomly rebooted again.

Originally Posted by CNCRob I also changed the 100watt power supply that came standard in it to a 300watt power supply, still didn't fix it.

NC Cams,

It seems that CNCRob has already tried a different power supply, to no avail.

[NC Cams]

One more idea: we have some cam design software. That is not specifically relative but it could be.

IT seems that the memory handler in the program did not like a certain bramd of chipsets. The software had this wierd proclivity to do funny things when it was run on a computer with a certain chipset.

Run it on ANY other computer and it would run fine - all day - run just fine. Take the HDD and plug it into a PC with a m/b having this certain chipset, poof, crash city.

From this I learned that a PC isn't a PC....

[HayTay]

Originally Posted by NC Cams IT seems that the memory handler in the program did not like a certain brand of chipsets. The software had this weird proclivity to do funny things when it was run on a computer with a certain chipset. Run it on ANY other computer and it would run fine - all day - run just fine. Take the HDD and plug it into a PC with a m/b having this certain chipset, poof, crash city. From this I learned that a PC isn't a PC....

This is too true and you have a good point NC Cams. If I remember correctly, most programs when compiled can have their code optimized for a certain chipset or set of chipsets. Not all CPU chipsets, even among the same vendor, use the same function calls or code within the processor.

I used a payroll/time clock software application many years ago, it ran fine on an Intel 286, 386 or 486 CPU. Load the bugger on and Intel Pentium, Cyrix or AMD based system and it was, as you said, crash city.

[Megahertz]

Maybe it is an EMI problem. What if electrical noise is getting into your PC through the motor contol board. When coils (stepper motors, solenoids, etc..) get turned off they have alot of energy that needs to go somewhere. Did you/can you isolate the driver board?

[HayTay]

Just had a memory epiphany, pop the cover and take a close look at ALL of the capacitors on the motherboard to see if any are buldged, leaking or have burst. If so, your motherboard suffers from "capacitor plague" or "burst-capacitor syndrome". I saw quite a few failed motherboards due to this problem several years ago and forgot about it until I re-read your initial post about the Compaq Presario 600 Mhz PC with an Intel Celeron uProcessor (from several years ago, hello!). It only takes a few minutes to check the suspect components.

A quote from http://cquirke.mvps.org/badcaps.htm:

"Affected systems may present with:

* Intermittent hard lockups requiring button reset
* Analog-level display shimmer / waviness (inbuilt SVGA)
* Spontaneous resets
* Failure to POST, or power up at all"

You can read all about it by clicking on the links below:

http://cquirke.mvps.org/badcaps.htm
http://www.badcaps.com/
http://www.answers.com/topic/capacitor-plague
http://www.smartcomputing.com/editor...2r04/12r04.asp
http://news.com.com/PCs+plagued+by+b...3-5942647.html

[Brian P]

I had a very similar problem with my brothers computer.. tried everything.. turned out to be the power supply.. Buy a High Quality supply.. don't cheap out.. 500W+

He originally had a 350W. It would reboot when the CD was running.. Doesn't take much to trip the supply. Espeacially if it's built with cheap components.

Just a thought.

[john_s]

Could also be worth checking that the fans in the system are running properly and heatsinks are clear - check the CPU, graphics card, and chipset heatsinks and fans (if it has them). A blast of compressed air (or airduster) is great for clearing dust from fans.

John.

[davesaudio]

Originally Posted by Brian P I had a very similar problem with my brothers computer.. tried everything.. turned out to be the power supply.. Buy a High Quality supply.. don't cheap out.. 500W+ He originally had a 350W. It would reboot when the CD was running.. Doesn't take much to trip the supply. Espeacially if it's built with cheap components. Just a thought.

Yes one should buy a good PSU. If it is a good one it does not need to be 500W. Chrome and leds don't necessarily make them good either. Cheap supply vendors tend to over-inflate their specs.
Good Value Brands - Fortron/Sparkle, HEC /Heroichi, Channel Well/Compucase.