Windows 98 SE (build 4.10.2222)
467 megahertz Intel Celeron

Board: i440BX-W977 (BM6), bus clock: 66 megahertz
BIOS: Award . 07/01/1999

Drives:
Generic floppy disk drive (3.5")
Generic IDE hard disk drive (12.06 GB) -- drive 0
Generic IDE hard disk drive (30.71 GB) -- drive 1
Maxtor 6 Y200P0 [Hard drive] (203.86 GB) -- drive 2, rev YAR4
CD-ROM drive: TEAC CD-W54E

Controllers:
Standard Floppy Disk Controller
Intel 82371AB/EB PCI Bus Master IDE Controller
Primary IDE controller (dual fifo)
Secondary IDE controller (dual fifo)

Bus Adapters
Silicon Image SiI 0680 ATA/133 Controller
Intel 82371AB/EB PCI to USB Universal Host Controller

When I switch on (using the button-press on the front of the machine - all other toggle switches are left on), the fans in the PSU and Celeron whirr for half a second and then stop, and booting does not occur.

By trial and error I have narrowed the problem to the Maxtor HD.

If I power off after the non-start, pull out the power connection to the Maxtor HD and then power on and press the button, the computer starts normally. I allow Windows to open fully, and then shut down via the Start button, power off, reconnect the power for the Maxtor HD, power on, press the button, and all starts normally.

In other words the presence of the Maxtor HD prevents booting on first switching on, but after disconnection, rebooting, power down and reconnection, the Maxtor HD presents no further problem.

Any suggestions?

Is it safe to assume the maxtor is a second hard drive? I would get the system booted and download the diagnostic software from the Maxtor site.

The Maxtor is the third hard drive, run from a supplemental board - I presume it's the Silicon Image SiI 0680 ATA/133 Controller quoted in the system description. I'll take your advice and download the Maxtor software.

I have now downloaded and used PowerMax 4.21 to test the HD in question, and it passes all the tests. From one point of view that's not surprising, as once I get the system running I have no problem from the HD.

Does the fact that the cooling fans operate for about a second before everything shuts down give any indication? It's as if there is some monitoring device that assesses loading and cuts in to prevent damage; and perhaps the PSU feels it can't cope with the load of this HD from a cold start but is then capable once it has warmed up with the HD disconnected temporarily. My description seems to suit an automobile rather than a computer, but it's the best I can do to shift the focus from the HD itself to some other component that's affected initially by the presence of the HD but not on subsequent bootings. I have not tested how long the computer can be switched off without suffering from this startup problem.

Testing the hard drive is the first step, if it comes up clean, the next step is replace the ribbon and power cables one at a time and see what happens. If that does not resolve the problem I would look at the controller card or the PSU.