Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ucbvax!decwrl!hplabs!hpda!hpcuhb!hp-sde!hpfcdc!hpfclp!mike From: mike@hpfclp.SDE.HP.COM (Michael Bishop) Newsgroups: comp.sys.ibm.pc Subject: 386 Computer Problems Message-ID: <6640011@hpfclp.SDE.HP.COM> Date: 6 Sep 88 19:25:24 GMT Organization: GTD -- Ft. Collins, CO Lines: 108 I'm having a serious problem with my Dell Model 310 computer system which I have not been able to solve so far. I thought I would share my experiences, then solicit ideas and comments from the net. Perhaps others have had similar problems. I've owned the system for about 6 weeks now. First the machine: Original Configuration: 20 Mhz 386 (AT Compatible) 1 MB main memory VGA Color Plus Monitor 40 MB Hard Disk 40 MB Tape Backup 101 Key Enhanced Keyboard I Added: 1 MB RAM (bought from Dell) Microsoft Bus Mouse w/ mouse driver 6.24 The symptoms: The system crashes periodically. However, there isn't a simple set of commands, or keystrokes, or mouse movements that produces the failure every time. The problem appears intermittently. I know it has crashed when it refuses to accept input and the input buffer overflows. I've had it crash with MicroSoft Word 4.0, MS Windows 386, Leisure Suite Larry (a game), and other programs, so I do not think the problem lies in the software I'm running. Sometimes I can soft re-boot, other times I'm forced to cold start the machine. What I've done so far: At first I thought that the problem was either software related or configuration related. It seems that the system only crashes when I'm generating input from the mouse or keyboard. I can run a simple graphics program (output only) for days without the system crashing. However, when I'm using MicroSoft Word and heavily using the mouse and keyboard, the system crashes regularly. I called MicroSoft and told them what was going on. They seemed to think that my problem was due to an "old" mouse driver. I was running the 6.11 version of the mouse driver. They sent me a new mouse driver (6.24). I tried it out, quickly making the system crash again. The next thing I tried was powering up the system without the mouse hardware and without installing a mouse driver. I was still able to crash MS Word quickly by just using the arrow keys to drive around in a file. I could crash Word in about a minute or less. Then I suspected possible BIOS bugs. The Dell Model 310 allows you to run the BIOS in RAM for faster speed, but if that RAM was getting clobbered inadvertently, I figured it could crash the system. So I turned the Fast BIOS and Fast Video modes off so that I could run all of the firmware out of ROM. The system still crashed. Finally, I turned the system speed down from 20 Mhz to 8 Mhz. A-ha! The problem went away. I could not crash the system at 8 Mhz. Suspecting the hardware more and more, I called Dell Computer. I explained the problem; They, of course, had never heard of any problems like mine, but being the good guys that they are, they sent me a new motherboard. A service man came out and transferred my additional 1 MB of RAM from the old motherboard to the new motherboard. Then he installed the new motherboard and powered up the system. It seemed to run just fine. All of the techniques and methods that I was using to make the system crash (at 20 Mhz) had no effect. I was somewhat confident that that the problem was fixed. (Of course the real test would be making it through an 8-hour Word session without the system dying.) The service man left taking my old motherboard with him. Well, to make a very long story somewhat shorter, I crashed Word again about an hour into a session. It seems that the system still crashes, but far more *infrequently* than before. So far, I've only been able to crash the system once; the symptoms, however, are the same. Input locks up and I'm forced to re-boot. (BTW, I've tried using Word's CNTL-ALT-/ command to clear the input buffer, this has no effect as far as unfreezing the system. I've also tried running Word in Text Mode, but it still crashes.) My next experiment is to pull the 1 MB of additional RAM and see if I can crash the system as *originally* configured. This is rather risky because of static electricity and such. BTW, all of the computer diagnostics (e.g., the Dell System Analyzer) say the system is A-okay, including the RAM test. Prognosis: I'm tempted to call Dell and have them ship me a whole new system, but I'd really like to know what's wrong with the one I've got. If I had to take a guess, I'd say with fair confidence that it's a hardware timing-related problem, and that the new motherboard solved it a little bit, but not completely. Another possibility is defective SIMMs (memory) but it seems that would have produced a similar failing frequency on both motherboards. So I think the "bad memory theory" is somewhat less likely than the "bad system timing" theory. Isn't this fun? Does anyone have a "reasonable" suggestion for helping me to isolate and solve this problem? I've had the computer for over a month now but have not been able to use it very much because of these problems. Thanks for all of your ideas.** Michael Bishop Hewlett-Packard/Graphics Technology Division Ft Collins, CO. UUCP: {ihnp4,hplabs}!hpfcla!mike-b Internet: mike%hpfclp@hplabs.HP.COM ** Related to this topic :-).