Hi, Matt.    Back on 3/3, we were talking about - -

 MM> Over the years, I _have_ repeated this with different CPUs at different
 MM> speeds, on different brand MBs, all with the same results.  I _must_
 MM> start with a faster CPU to be able to get back into the system to set
 MM> things back to normal.

Have you noted whether the same problem occurs on boards which have
jumpers for setting the clock-multiplier, or have you seen it only on
the boards which "autodetect" the CPU?  Dang!  What good is an
autodetect function if it doesn't work, or only works _one_ time?

I've seen what you described a time or two, where I put a PII-266 in a
board and it showed up in POST as a 233.  I guess I could get video
since it was an underclock, and then I got into SETUP and toggled it
back up to 266.

 MM> The boards you get to work with probably have no RAM on them either to
 MM> help give you a clue, such as if the RAM were PC66 or PC100, etc., and
 MM> would introduce an additional variable guessing what might have been
 MM> there before.

You got it -  no cpu chip, no ram, no notes, no nothing, but a Director
who wants us to "get them working".  He does, however, go along with us
most all the time when we finally give up on them.  It does bug me,
however, that maybe if we had held back a PII-333 chip or so for
testing, some of them may have sprung to life.

Speaking of overclocking - - I have a Celeron 300a here which I've seen
get video on a board jumpered for 100 fsb and clockmul of 4.0. AFAIK,
this was the chip release that finally got Intel's attention about
overclocking, and they subsequently took countermeasures. I guess maybe
I should take it downtown with me, and give it a try in some of these
boards before we finally give up on them.

 JH> We've seen a number of boards with those "bulging tops" on the
 JH> large caps near the cpu, and when those boards don't work right off,
 JH> we give up on them especially quickly.

 MM> Changing those caps has become so common now, I've begun keeping notes.
 MM>  I am finding that only on the 400 - 500 CPU speeds.  350 and below
 MM> seem to be OK, and 533 and above seem to be OK.  Those 400-500 speed
 MM> CPUs must put additional load on _part_ of the power system, or put out
 MM> noise spikes resonant with those size capacitors to cook them.  Just a
 MM> WAG, but a peculiar condition nonetheless.

Hmm.  Here's an abbreviated distillation of what my book (Scott Mueller,
12th Ed) said about some of those - - maybe he is correct for once
(hee). Sorry, this edition doesn't have info on PIII.

CHIP            FSB     Die     Volts   Watts
PII-233         66      0.35    2.8     34.8
PII-266         66      0.35    2.8     38.2
PII-300         66      0.35    2.8     43.0
PII-333         66      0.25    2.0     23.7
PII-350         100     0.25    2.0     21.5
PII-400         100     0.25    2.0     24.3
PII-450         100     0.25    2.0     27.1

CHIP            FSB     Die     Volts   Watts
CELERON
Cel 300A        66      0.25    2.0     19.05
Cel 366         66      0.25    2.0     21.7
Cel 400         66      0.25    2.0     23.7
Cel 466         66      0.25    2.0     25.7
Cel 500         66      0.25    2.0     27.2
Cel 566(FCPGA)  66      0.25    1.5     14.9
Cel 600(FCPGA)  66      0.25    1.5     15.8

The big power users were the early PII thru 300 MHz.  The PII333 and
350 data looks kinda funny.  But, looks like maybe boards in the 400-500
range which may be killing capacitors could have a prob in the way they
support those chips with core voltages of 2.0?

Just FWIW -  what do you think?

 - - -  JimH.

... Inquiring minds want to know. - Bubba
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