The Dead PC

By Anthony Olszewski
Copyright 1997

These notes are only meant to illustrate how I go about working on a machine. I'm not encouraging anyone to work on their own system. In any event, if you do any damage, direct or incidental, you are assuming complete responsibility and liability!

ISA 486 Motherboard (CPU Not Installed)

This article focuses on PCI PENTIUMs and the 286 (AT), 386, and 486 class machines of ISA architecture, including the overwhelming majority of clones and compatibles produced over the last ten years. In general, it does not matter if the processor chip was manufactured by INTEL or not. EISA and VLB systems are based on the same architecture and these notes directly apply. Extensions incorporated into EISA and VLB are very often self-evident and, in any case, will be covered in future articles.

How do you know if your machine is ISA? If it is a 286, 386, or 486 and you're not sure, then bet that it is ISA! Even some early PENTIUMS or 486s upgraded to PENTIUM are ISA.

A Standard System Unit

A motherboard, rather than a backplane design is assumed. Again, most often, the same investigative flow chart can be followed. WYSE and NEC are two of the biggest manufacturers of backplane systems.

A Backplane System. Most Components, Including the CPU, Are On Cards

Pre-ISA machines (original PC, XT, and clones an the PCjr) are another ball of wax entirely. A few of the ideas that you find here will be useful, but not many. To learn about these primitive, but still useful computers, seeThe Garbage Can PC.
XT Clone. Note That All The Slots Are 8 Bit
IBM PS2 50 -- Proprietary Hard Drive, Floppy Drive, Motherboard, Power supply, ...
MCA (IBM PS2) machines incorporated many changes. The same troubleshooting methodology can very often be used, but many differences exist! Common troubles are the 160 series error codes and the 305 error code in the 55SX.

For a vast and comprehensive treatment of the PS2 systems, read Chris Feeny's PS2 FAQ.

A desktop or server is assumed. Notebooks are not covered in this document.