[Ti] TiBook Will Not Boot Unless Reset

[Lloyd Smith]

TiBook, 400 MHz, 10.4.10, 640 MB SDRAM

One morning, I pressed the power button, clicked on FireFox to open, then I
moused over to the icon of one of the partitions of the internal hard drive.
(I use an external Kensington optical wired mouse and the book is seldom run
on battery or moved from stand in past year.) As the cursor was moving
across the screen, it froze. And it will not boot full using either external
FireWire drive or internal drive. Tried the emergency restart procedure. It
makes the usual start-up sound, lights flicker... then nothing happens.

Unless I depress the reset button, then it will boot all the way.

Unless I depress the reset button, I can do / observe the following:

I can restart from an external FW drive, but cannot boot from a shutdown.
For boot partitions, I use one on the Ti book, two on the Newer and two on
the LaCie (one each external drive is the most recent backup, rotated one
week at a time.) Restart, fine. Shutdown and start, never. (Unless the PMU
is depressed.)

I can see the small "on" lights on the USB plugs and the power light on a
Newer USB 2.0 drive
flashes green - then goes out as though no signal is reaching the drive
through the PCMCIA slot.
I CAN use Target mode, but that is all. Unless the reset button is
depressed, no boot.

Three replaceable batteries tried. Recharging internal battery does no good.
Disconnecting all USB and FW devices does nothing.

I can turn the machine off (the drive is running but no signals sent to
screen, or enough to do more than send a small current to the uSB ports, so
the "on" light to a small hub will light, but not enough to light the
optical mouse) by holding the power button for the usual 5 - 10 seconds.

I have booted from FireWire drives (both Newer Technologies and LaCie
Porsche Design) and run all practical tests. The SmartReporter log shows the
internal drive to be in good order.

I can either leave on all the time, or after I shut down, use a paper clip,
depress the PMU button to level one (tried full-depress so resets of time,
etc., required), press the power button, and it takes just a little longer
than normal to boot, but the progress bar does appear and moves the entire
width, and all features, including modem, works fine.

Suggestion appreciated.

N.B. It seems that Verio blocked mail for a while. Registered as
lloyd at smithrep.com