Hello!

It's been quite a while since I have done any work with my retro PC. Recently I've picked up a Siemens D1107 B11 GS1 motherboard and a Slot 1 Pentium III 700 for it, but it doesn't run smoothly at all.

The thing is, it appears to do things out of the blue whenever it feels like it. When I first set up the MoBo, it would give me random "HIMEM.SYS is missing" errors when booting Win98. They were infrequent and completely unrelated to both the memory and the hard drive I'm using; they are confirmed to be fully operational. On top of that, as of 2 days ago, these random errors cease to exist, as the PC has somehow stopped doing them for no reason.

With that out of the way, there are some other problems with it. One of the 2 USB ports only provides power to *certain* devices such as speakers, and refuses USB Flash Drives and input devices (only the bottom USB port accepts them). Not only that, this one USB mouse I have outright causes the system to hang before it even gets to POST. Only this one, by exception.

Also, when I updated the BIOS to the latest version and was reinstalling Win98, it started to hang at the plug n play hardware detection part. On every 2nd attempt, the installation finished but disabled some ACPI related entry in Device Manager. It stopped doing this when I reverted to the previous BIOS.

Now, for the biggest of my concerns, it appears to have gone completely mad after I've installed the 700MHz Pentium III (it had a 500). Whenever I insert **CERTAIN**
CDs (all written, different brands) into the CD Drive, the computer restarts. No BSOD, just a surprise restart. Happens while POSTing, after it and also in Windows.
The CD Drive also seems to get called at very random times when it shouldn't be such as near the end of the boot sequence or while the system is being turned off.

The strange thing is, once it has booted into Windows, for as long as I've run this motherboard, it doesn't crash, except for the new CD issue (it has to be provoked). None of the previous issues caused it to malfunction while it was running and I can play demanding games as well as 3DMark 2000 and it won't crash.

Currently I'm thinking it has to be a capacitor issue (one of them is dented, the others seem fine) or something with my PSU. Either way, I'm looking forward to fixing it and I'm hoping I can get help here on VOGONS.