2 Jul
1999
2 Jul
'99
6:14 p.m.
Hello Dick:
In a message dated 7/2/99 6:15:07 PM Eastern Daylight Time, edick(a)idcomm.com
writes:
IBM had people who were really worried about noise,
hence wouldn't put a
meaningful fan in the box. That little thing in the PSU (which dies more
often than any other single component in any PC)
Not to doubt your word, but as owner of a small PC repair shop, my experience
(and records) would suggest that the following components have a higher
failure rate than power supplies or their fans. In order from highest
failure rate:
1) modems -- extremely susceptible to spikes -- our most common repair
2) CD-ROM drives -- easily damaged by jarring the unit -- we sell a lot of
replacements
3) floppy drives -- usually a victim of grit which is sucked in through the
drive by the power supply fan!
Side note: In '88 I had a gig with Gulf Oil/Cumberland Farms. Being a True
Blue shop, MIS insisted on nothing less than PS/2-80s at forty loading
terminals. About three months after installation, the floppies began to
fail. Inspection revealed that since Big Blue, in their wisdom, had failed
to build the little closure flap into the drives (probably saved them 10
cents per unit), these machines were not suitable for use in an industrial
environment without modification (replacing the drive).
Modifying these critters cost IBM a boatload on just this one project; I'm
sure there were many more.
Regards,
Glen Goodwin
0/0
2 Jul
2 Jul
6:24 p.m.
Side note: In '88 I had a gig with Gulf
Oil/Cumberland Farms. Being a True
Blue shop, MIS insisted on nothing less than PS/2-80s at forty loading
terminals. About three months after installation, the floppies began to
fail. Inspection revealed that since Big Blue, in their wisdom, had failed
to build the little closure flap into the drives (probably saved them 10
cents per unit), these machines were not suitable for use in an industrial
environment without modification (replacing the drive).
As one who has spend quite a bit of time in industrial environments, I
would say that MIS department was a bunch of Bozos for not getting
industrial machines. Basically ANY floppy that spends its life at a
loading dock is going to die very quickly, followed in short order by the
power supply and keyboard.
William Donzelli
aw288(a)osfn.org
8 Jul
8 Jul
2:07 a.m.
> IBM had people who were really worried about
noise, hence wouldn't put a
> meaningful fan in the box. That little thing in the PSU (which dies more
> often than any other single component in any PC)
Not to doubt your word, but as owner of a small PC
repair shop, my experience
(and records) would suggest that the following components have a higher
failure rate than power supplies or their fans. In order from highest
failure rate:
1) modems -- extremely susceptible to spikes -- our
most common repair
Modemfailure due spikes ? Just out of couriosity - do you still
have telegraph like overhead single wire telephone connections
and no protective devices in your area ? (Thats just the only
way I can imagine to become the modems into #1 failing devices)
Gruss
H.
(Just back from Oslo)
--
Traue keinem Menschen der 5 Tage blutet und immer noch nicht tod ist.
3:40 a.m.
Hans Franke wrote:
As a computer tech in SW Florida, My number one service call isreplacing Blown
modems. Damaged by spikes on the telephone lines.
SW Florida is the "Lightning Capitol", more lightning strikes here than
anywhere else in the united states..
Modems are the number one reason for service calls in this area..
Phone line surge protectors are a must in this part of the states,
But they get "Fried" in direct strikes also..
Phil...
> IBM had
people who were really worried about noise, hence wouldn't put a
> meaningful fan in the box. That little thing in the PSU (which dies more
> often than any other single component in any PC)
Not to doubt your word, but as owner of a small
PC repair shop, my experience
(and records) would suggest that the following components have a higher
failure rate than power supplies or their fans. In order from highest
failure rate:
1) modems -- extremely susceptible to spikes --
our most common repair
Modemfailure due spikes ? Just out of couriosity - do you still
have telegraph like overhead single wire telephone connections
and no protective devices in your area ? (Thats just the only
way I can imagine to become the modems into #1 failing devices)
Gruss
H.
(Just back from Oslo)
7:12 a.m.
"Hans Franke" <Hans.Franke(a)mch20.sbs.de> wrote:
Modemfailure due spikes ? Just out of couriosity - do you still
have telegraph like overhead single wire telephone connections
and no protective devices in your area ? (Thats just the only
way I can imagine to become the modems into #1 failing devices)
Hi
For most things, the surge protectors on phone lines are OK
but if you are within a 1/2 mile or so of a lightning hit on
the phone line, even shielded lines, those small MOVs that
they put on modems are history. Phone lines, and well protected
phone lines at that, are one of the most common sources
of lightning electrocution.
I once bought a pile of modems that were returns. Almost every
single one had some high current discharge damage. I suspect
that most was lightning caused. In one case, you could see where
it had arced across a 1/8" gap and burned the lead clean of
one of the parts.
It is foolish to think that any form of protective device,
short of complete isolation will give 100% protection against
a close lightning strike. If you live in an area where lightning
is rare, you may not be aware of the dangers of even using your
telephone. A device with a guarantee against lightning damage,
doesn't mean that it will withstand a strike, only that they
will replace it when it does.
If you live in one of the areas with a lot of lightning strikes,
and you leave your modem plugged in, you'll surely have your
modem damaged in time. You may even be the damged part if
you are connected.
Dwight
7:47 a.m.
On Thu, 8 Jul 1999, Dwight Elvey wrote:
For most things, the surge protectors on phone lines
are OK
but if you are within a 1/2 mile or so of a lightning hit on
the phone line, even shielded lines, those small MOVs that
they put on modems are history. Phone lines, and well protected
phone lines at that, are one of the most common sources
of lightning electrocution.
This is only true for overhead lines, and not when they are buried under
the street, correct? Actually, some of the main lines are fiber-optic now,
which shouldn't carry a surge.
--Max Eskin (max82(a)surfree.com)
http://scivault.hypermart.net: Ignorance is Impotence - Knowledge is Power
9:03 a.m.
Max Eskin <max82(a)surfree.com> wrote:
This is only true for overhead lines, and not when they are buried under
the street, correct? Actually, some of the main lines are fiber-optic now,
which shouldn't carry a surge.
Hi
Resent experiments in Florida with underground wires has shown
that even this doesn't stop a large strike. Fiber-optics
doesn't carry any current unless it is metal shielded
( to protect against roof rats and sewer rats ). Still
most people have wire lead-ins to their houses. The good
rule of thumb in a lightening storm is only use a cellular
phone and stay away from things like phones and TVs that
have wires going outside.
Dwight
9:05 a.m.
On Thu, 8 Jul 1999, Max Eskin wrote:
On Thu, 8 Jul 1999, Dwight Elvey wrote:
Not necessarily; it depends on the conductivity of the ground at the
spot where the lightning strikes. I've seen underground power cables
damaged by lightning that made its way through 1 meter of soil and
concrete. The path of conduction was a beautifully cristalized mess.
Carlos.
Phone lines, and well protected
phone lines at that, are one of the most common sources
of lightning electrocution.
This is only true for overhead lines, and not when they are buried under
the street, correct? Actually, some of the main lines are fiber-optic now,
which shouldn't carry a surge. 
8:16 a.m.
At 11:08 AM 7/8/99 +1, you wrote:
experience
Yes I have overhead lines and they have protective devices. But the
Telco's idea of protective devices is a spark gap! Yes, seriously.
But I also live in Central Florida and this is the lightning capital of
the world! A lightning strike on the phone lines will take out the MODEMs
for miles around. I've lost several MODEMS and TVs to lightning and it
ALWAYS came in through the telephone and cable TV lines and not the power
lines. I even lost the keyboard buffer ICs on an old DTK turbo XT due to a
nearby strike that some how induced a surge in the keyboard cable. I now
have protective devices on ALL lines and not just the power lines. The
devices have saved my equipment but they get blown out in the process.
Frankly I wonder if it's worth it. A good telephone line protector cost
more than a MODEM does.
Joe
> > IBM had people who were really worried about noise, hence wouldn't put a
> > meaningful fan in the box. That little thing in the PSU (which dies
more
> often
than any other single component in any PC)
> Not to doubt your word, but as owner of a small PC repair shop, my (and records)
would suggest that the following components have a higher
failure rate than power supplies or their fans. In order from highest
failure rate:
1) modems -- extremely susceptible to spikes --
our most common repair
Modemfailure due spikes ? Just out of couriosity - do you still
have telegraph like overhead single wire telephone connections
and no protective devices in your area ? (Thats just the only
way I can imagine to become the modems into #1 failing devices)
7:45 a.m.
On Thu, 8 Jul 1999, Joe wrote:
have protective devices on ALL lines and not just the
power lines. The
devices have saved my equipment but they get blown out in the process.
Frankly I wonder if it's worth it. A good telephone line protector cost
more than a MODEM does.
Actually, I'm not at all convinced that the 'surge protectors' are as
reliable as they claim. I have one that refused to blow several times,
when I shorted a cable connected to it. Another one (working properly)
_did_ blow.
--Max Eskin (max82(a)surfree.com)
http://scivault.hypermart.net: Ignorance is Impotence - Knowledge is Power
9147
days inactive
9153
days old
9 comments
8 participants
participants (8)
-
aw288＠osfn.org -
cem14＠cornell.edu -
elvey＠hal.com -
Glenatacme＠aol.com -
Hans.Franke＠mch20.sbs.de -
max82＠surfree.com -
musicman38＠mindspring.com -
rigdonj＠intellistar.net