[comp.sys.ibm.pc] Leaving AT on overnight

german@uxc.cso.uiuc.edu (08/07/87)

I have several PC/ATs that have been on almost continously for 3 years.  I have
not noticed any problems with the hardware.  I think you can make arguements 
both ways on what is best for the machine, but if the machine is going to be 
used (network server, remote access, etc.) I would have no qualms about letting
it run all night.  (provided the room was airconditioned I suppose)
         Greg German (german@uxc.CSO.UIUC.EDU) (217-333-8293)
US Mail: Univ of Illinois, CSO, 1304 W Springfield Ave, Urbana, IL  61801
Office:  181 Digital Computer Lab.

hundt@wind.bellcore.com (tom hundt) (08/07/87)

>running a job every so often to park the hard disk head

I have a little thingy called "timepark" which parks the head
after 3 minutes.  I *think* it works on ATs...

Anybody interested?


 /-^-\  Thomas M. Hundt / BELLCORE Morristown NJ / hundt@bellcore.bellcore.com
 |   |  {seismo|ihnp4|ucbvax|decvax|ulysses|allegra|clyde}!bellcore!hundt
/--_--\  

jons@islenet.UUCP (Jonathan Spangler) (08/13/87)

In article <174200062@uxc.cso.uiuc.edu> german@uxc.cso.uiuc.edu writes:
>
>
>I have several PC/ATs that have been on almost continously for 3 years.  I have
>not noticed any problems with the hardware.  I think you can make arguements 
>both ways on what is best for the machine, but if the machine is going to be 
>used (network server, remote access, etc.) I would have no qualms about letting
>it run all night.  (provided the room was airconditioned I suppose)
>         Greg German (german@uxc.CSO.UIUC.EDU) (217-333-8293)

Our building shuts off the air conditioner at between 8 and 8:30pm every 
evening. I run a bulletin board off of an AT clone with no problems. The
board has been running since about May. I guess room temperature is a relative
thing, but temperature changes are not as dramtic here as they are elsewhere.
:-)

Aloha,

-- 
Jonathan Spangler
{ihnp4,vortex,dual}!islenet!jons
	OR
jons@islenet.hawaii.edu

mellman@ttrdd.UUCP (Thomas Mellman) (08/13/87)

In article <768@custom.UUCP>, boykin@custom.UUCP writes:
> 
> In article <1246@bloom-beacon.MIT.EDU>, voyager@athena.mit.edu (Center for Space Research) writes:
> > 
> > Could anyone give me some info on the bad, good, not-so-bad points
> > related to [leaving his AT on overnight].
> 
> Without a doubt, leave the machine on.  Leave it on 24hours a day
> 7 days a week.  The electronics will last significantly longer
> that way.  Most computers die as they're being powered up or down.
> ...
> As for the bearings in the disk drive, they won't be any worse for
> the wear either.

I don't know about that.  My disk drive specs rate my drive's life at
11,000 hours.  I guess I kind of hoped that I could expect more than
1 and 1/4 years out of it.

As far as that old argument that the electronics don't like power cycling,
how many terminals (as a model for pc's that's been around alot longer)
has anyone come up against whose electronics have failed?  Usually, they
just get so obsolete that nobody wants to use them anymore, or the
keyboard becomes unusable.  I think I can say that I've never seen a
terminal that didn't work.

NU013809@NDSUVM1.BITNET (Greg Wettstein) (08/14/87)

As the computer coordinator for the College of Pharmacy I have been dealing
with the on vs off controversy for about 8 years now.  It has been my
experience that computer equipment and peripherals which are left on
continuously have far fewer problems than those which are cycled with any
degree of consistency, even once a day.
     
The first personal computer I dealt with after having a series of Data
General mini-computers was a Zenith Z-158 with one of the first 10 megabyte
hard disks which ZDS started putting in their computers.  It was left on
24 hours a day for 2 to 2 1/2 years before the (what would be considered
the fairly primitive) hard disk gave out.
     
I have another Zenith Z-158 with a Seagate ST-225 hard disk in one of
our hospitals which has been running continuously now for 2 years with
nary a glitch.
     
On the other hand our research group on campus has an IBM PC which is
now on its third hard disk in about three years.  The first disk lasted
only about 1 year as it was cycled on and off every time somebody wanted
to use it.  I managed to convince them that they should at least let it
run all day and turn it off at night it they wanted to.  This was done
with the second hard drive and this one lasted slightly longer than a
year.  I put a Seagate ST-225 in when the second drive burned out and
strongly advised leaving it run 24 hours a day.  The drive has been
running flawlessly for over a year now with no difficulty.
     
A good friend of mine who teaches in the Electrical Engineering department
here at NDSU was the individual who started me on my crusade to keep
equipment running all the time.  He had told me that as far as he knows
there have been no definitive studies that indicate that semi-conductor
devices (integrated circuits) "wear out".  In the vacuum tube era (which
I experienced first hand) this was not the case.  These devices depended
on emission from thorium-oxide coated filaments.  The filaments had a
finite lifespan which could be preserved by powering the device down when
not in use for extended periods of time.  What appears to be the case with
semi-conductor devices is that while they do not "wear out" they can be
damaged by voltage spikes and power surges induced by the power cycling
process.
     
One of the individuals posting a message in this chain indicated that he
had never heard of a terminal wearing out.  I wish that our organization
had his luck.  Our first attempt at word processing was with a multi-user
product called T.I.P.S. marked by IPTC of Palo Alto California.  This
word-processor supported our five secretaries and was run under RDOS on
a Data General Nova/4X.  Each secretary had an ADM-5a as a terminal.  I
advised them to leave the terminal on all the time and to simply turn down
the display whenever they wanted to leave the terminal for longer than
5 minutes.  I couldn't convince them that this was a good idea and the
terminals got turned off every night and sometimes a couple of times a
day.  To make a long story short none of those terminals lasted much over
a year, all died of various electronics problems.  At the time we purchased
the terminals we actually bought six terminals and the sixth went on the
Nova as the operator console.
     
That terminal ran continuously for three years 24 hours a day until we
sold the Nova and went to PC's.  I moved the terminal down to my lab
office and its still running 24 hours a day, 2 years after we took it off
the Nova.
     
These results are not scientific or statistically rigorous but they do
serve as examples.  My experience has taught me to worry more about
environmental considerations such as excessive heat and the biggest problem
(especially here in the prairie) large amounts of dust and dirt getting
into the equipment.
     
                                   As always,
                                   G.W. Wettstein
                                   NU013809@NDSUVM1
     
     
When not at the above E-MAIL address I can be found in Davenport, North
Dakota, roping the hind feet of Hereford cattle . . . very rapidly.......
     
     

guardian@laidbak.UUCP (08/14/87)

In article <202@ttrdd.UUCP> mellman@ttrdd.UUCP (Thomas Mellman) writes:
>In article <768@custom.UUCP>, boykin@custom.UUCP writes:
>> 
>> Without a doubt, leave the machine on.  Leave it on 24hours a day
>> 7 days a week.  The electronics will last significantly longer
>> that way.  Most computers die as they're being powered up or down.
>> ...
>> As for the bearings in the disk drive, they won't be any worse for
>> the wear either.
>
>I don't know about that.  My disk drive specs rate my drive's life at
>11,000 hours.  I guess I kind of hoped that I could expect more than
>1 and 1/4 years out of it.

I've seen the average life of an AT to be about two years before breakdown.
Most of the PC's I've installed have had hard disk falures or general problems
within about two to three years.  If you wish to build a unit that  will 
survive for a while, then I would get the specs on the hard disk (much as
boykin stated above) and also check to see how much heat the boards give off.

I've had my PC for about three years, running off-on for about 4-8 hours a
day (as I have needed it) and have had no problems.  I suspect though I 
should be seeing problems with it by the end of the year.  The hard disk
does not seem as quite as it was when I purchased it.


Harry Skelton
guardian@laidbak.UUCP

ayac071@ut-ngp.UUCP (William T. Douglass) (08/14/87)

In article <202@ttrdd.UUCP> mellman@ttrdd.UUCP (Thomas Mellman) writes:
>As far as that old argument that the electronics don't like power cycling,
>how many terminals (as a model for pc's that's been around alot longer)
>has anyone come up against whose electronics have failed?  Usually, they
>just get so obsolete that nobody wants to use them anymore, or the
>keyboard becomes unusable.  I think I can say that I've never seen a
>terminal that didn't work.

Well, let me enlighten you.  After 5 years working in a S/370 environment
with 3278/3178/3179 terminals, I have witnessed dozens of dying or dead
tubes (terminals.)  If fact, one of the local remote job entry sites decided
to power-off all terminals in its building over the week-end during summer
months, specifically because of concerns about heat-related damage.  This
was stopped after 3 weeks because the technicians determined that powering
up the terminals weekly was causing more failures than just letting them
run constantly.

I say, let 'er run.

Bill Douglass
ayac071@ngp.UUCP

karl@ddsw1.UUCP (08/15/87)

In article <202@ttrdd.UUCP> mellman@ttrdd.UUCP (Thomas Mellman) writes:
(Question was asked about leaving systems on overnight)

>> 
>> Without a doubt, leave the machine on.  Leave it on 24hours a day
>> 7 days a week.  The electronics will last significantly longer
>> that way.  Most computers die as they're being powered up or down.
>> ...
>> As for the bearings in the disk drive, they won't be any worse for
>> the wear either.
>
>I don't know about that.  My disk drive specs rate my drive's life at
>11,000 hours.  I guess I kind of hoped that I could expect more than
>1 and 1/4 years out of it.
>
>As far as that old argument that the electronics don't like power cycling,
>how many terminals (as a model for pc's that's been around alot longer)
>has anyone come up against whose electronics have failed?  Usually, they
>just get so obsolete that nobody wants to use them anymore, or the
>keyboard becomes unusable.  I think I can say that I've never seen a
>terminal that didn't work.

Hmmm... In my experience you'll get longer life from your system if you
leave it on all the time.  This comes from the 'school of hard knocks' -- I
have had the experience of multiple failures, usually immediately after
power-on.  Our office systems here are on 24 hours now, and we have yet to
have a failure in *ANY* component -- the only thing that is ever powered
down are monitors, and then only to prevent screen burn.

I've noticed that most drive failures occur during power-on.  We have
*never* had a customer report a failure during operation -- but have had
several failures during power up!

Case in point: My St4051.  It runs fine -- as long as you leave it running.
Turn it off, and it might not spin back up.  Defective?  Definately!
Something that would never happen if we never turned it off?  True as well.

Case in point #2: TRS-80 Model IV(s).  The unit had been in continuous
operation for about 4 years, and never had a failure.  Now that we only use
it occasionally, and power it down when not in use, it has become very
flakey and sometimes refuses to work properly.

What does all this mean??  You're better off leaving the unit *ON*.  Now,
this assumes that you have adaquate cooling for the system (ie: your office
doesn't go to 90 degrees Fahrenheit during the night).


-- 

Karl Denninger				UUCP : ...ihnp4!ddsw1!karl
Macro Computer Solutions		Dial : +1 (312) 566-8909 (300-1200)
"Quality solutions at a fair price"	Voice: +1 (312) 566-8910 (24 hrs)

magore@watdcsu.waterloo.edu (Mike Gore, Institute Computer Research - ICR) (08/17/87)

In article <5911@ut-ngp.UUCP> ayac071@ngp.UUCP (Bill Douglass) '> ' writes:
[in reply to]
In article <202@ttrdd.UUCP> mellman@ttrdd.UUCP (Thomas Mellman) '>> ' writes:
>>As far as that old argument that the electronics don't like power cycling,
[munch ...]
>I say, let 'er run.
...
>Bill Douglass
>ayac071@ngp.UUCP

	As another poster has pointed out the hard disk is the problem.
I have also found that hard disks reaching their MTBF is the greatest
risk from a cost point of view... It's more like a game of odd's taking into
account that most most semiconductor failures will happen during the
first month or so of use. In fact many people should _want_ such
problems to show up in these first first months of use so that warranty
repairs can still be made without cost. Thermo cycling tends to detach bonds 
or metalization layers that were defective during manufacturing early
in a products life time - on average... It's interesting to see
what happens when a fan in a power supply passes it's MTBF and dies [ they
must have clocks in them :) ] What happens next could be termed 
"short term burn in" ... :)


# Mike Gore 
# Institute for Computer Research. ( watmath!mgvax!root - at home )
# These ideas/concepts do not imply views held by the University of Waterloo.

steve@acich.UUCP (Steve Westfall) (08/18/87)

In article <3751@watdcsu.waterloo.edu>, magore@watdcsu.waterloo.edu (Mike Gore, Institute Computer Research - ICR) writes:
> In article <5911@ut-ngp.UUCP> ayac071@ngp.UUCP (Bill Douglass) '> ' writes:
> [in reply to]
> In article <202@ttrdd.UUCP> mellman@ttrdd.UUCP (Thomas Mellman) '>> ' writes:
> >>As far as that old argument that the electronics don't like power cycling,
> [munch ...]
> >I say, let 'er run.
> ...
> >Bill Douglass
> >ayac071@ngp.UUCP
> 
> 	As another poster has pointed out the hard disk is the problem.
> I have also found that hard disks reaching their MTBF is the greatest
> risk from a cost point of view... It's more like a game of odd's taking into
> account that most most semiconductor failures will happen during the
> first month or so of use. . .

The quality of the power supply in your community has a bearing on
this issue, and it can vary a lot even within the same power company's
service area.  I used to live in the city of Chicago, and I never had
any power problems at all.  I had a computer running day and night for
several years without any problem.  Then I moved to Lisle, one of
Chicago's western suburbs, which is served by the same company,
Commonwealth Edison, and I'm afraid to turn on my computer half the
time now!  I have lights blinking and power interruptions from one-half
second to several seconds at least once or twice a month.  I'm so paranoid
I save work files every couple of minutes.

(I think that some pervert at Commonwealth Edison knows that a lot of
AT&T employees live in the area, and, thinking that they all have
computers at home, he sits by a big switch and tries to screw up their
computers while they're at work! :-) )

-- 
Steve Westfall
Automated Concepts, Inc. - Chicago
(312) 346-8640
UUCP Mail:  {ihnp4|gargoyle}!acich!steve

john@hpcvlo.HP.COM (John Eaton) (08/19/87)

<<<<
< All IBM ATs (and most clones) have a key lock on the front panel to
< enable/disable the keyboard.  This will prevent access to the system
< even if it is running.  Of course, most non-AT PCs do not have this
< feature, although I have seen it on some clones.
----------

I like the way the Model 30 implemented its keylock. Locking the key switch
will short out two terminals on the motherboard and disable the keyboard.
One of the wires going to the switch is captured by a metal piece and held
right next to a hole that is covered by a rubber foot. If you lose your key
you simply remove the foot, reach in with a small pair of wire clippers and
your back in business.



John Eaton
!hplabs!hp-pcd!john

npollack@polyslo.UUCP (Neal Pollack) (08/19/87)

>In article <768@custom.UUCP>, boykin@custom.UUCP writes:
>
>As far as that old argument that the electronics don't like power cycling,
>how many terminals (as a model for pc's that's been around alot longer)
>has anyone come up against whose electronics have failed?  Usually, they
>just get so obsolete that nobody wants to use them anymore, or the
>keyboard becomes unusable.  I think I can say that I've never seen a
>terminal that didn't work.

Surely this person does not work around a large facility :-)

We have over 100 Terminals/Workstations/Macs/PCs in our facility.
DEC VT100 terminals fail more than anything. THE ELECTRONICS QUIT.
Specifically, the CRT driver board loves to smoke DURING SWITCH ON.
They NEVER quit while running, but when you switch them on, watch out.
TEKtronics graphics terminals flame out power supplies, XEROX 8000 Star
workstations burn CRTS, Disk drives, PC Boards, Power supplies.

In short, I see LARGE amounts of FREQUENT failures because of our huge
inventory of equipment.   The only terminals that seem to live forever
HERE (at our site ((disclaimer)) is the HP2622 and the ADM3a.

SO, please do not tell me that terminals never fail.  I will show you
thousands of dollars worth of repair bills.

FLAME OFF, settle down, drink gator-aid.

SUMMARY: The simple point is, equipment that we leave on continuously
has not failed.  The terminals and workstations that go on/off a lot
seem to quit regularly.

Take it for what its worth.



-- 
| Neal S. Pollack		|    ...!ihnp4!csun!polyslo!npollack	      |
| Computer Systems Lab		|    ...!{csustan,csun,sdsu}!polyslo!npollack |
| Cal Poly State Univ.		|    ...!ucbvax!voder!polyslo!npollack	      |
| San Luis Obispo, CA  93407	|    Voice: (805)-546-2147                    |

kai@ihlpa.ATT.COM (Irwin) (08/19/87)

In article <252@acich.UUCP>, steve@acich.UUCP (Steve Westfall) writes:
> In article <3751@watdcsu.waterloo.edu>, magore@watdcsu.waterloo.edu (Mike Gore, Institute Computer Research - ICR) writes:
> > In article <5911@ut-ngp.UUCP> ayac071@ngp.UUCP (Bill Douglass) '> ' writes:
> > In article <202@ttrdd.UUCP> mellman@ttrdd.UUCP (Thomas Mellman) '>> ' writes:
> > [munch ...]
> > 
> 
> The quality of the power supply in your community has a bearing on
> this issue, and it can vary a lot even within the same power company's
> service area.  I used to live in the city of Chicago, and I never had
> any power problems at all.  I had a computer running day and night for
> several years without any problem.  Then I moved to Lisle, one of
> Chicago's western suburbs, which is served by the same company,
> Commonwealth Edison, and I'm afraid to turn on my computer half the
> time now!  I have lights blinking and power interruptions from one-half
> second to several seconds at least once or twice a month.  I'm so paranoid
> I save work files every couple of minutes.
> 
> (I think that some pervert at Commonwealth Edison knows that a lot of
> AT&T employees live in the area, and, thinking that they all have
> computers at home, he sits by a big switch and tries to screw up their
> computers while they're at work! :-) )
> Steve Westfall

Well Steve, I live there too, and although I come home every other week and
reset the time on the 4 or 5 digital clocks we have in our house (I'm a heavy
sleeper, and I'm sick of resetting the time on the VCR so it just blinks)
I still leave my machine on, the power glitches rarly even make the machine
burp (capacitors don't ya know). I only come home to a rebooted machine maybe
once every couple of months, So again to all you listeners out there in netland
LEAVE IT ON!!

Ken A. Irwin
AT&T Bell Labs, Naperville
IHP 1A332
(312) 416-4485
                                                                               

                                                                               
                                                                               
                                                                               
                                                                               
                                                                               
                                                                               
                                                                               
                                                                               
                                                                               
                                                                               

master@uop.UUCP (Bechwghlarizaily) (08/22/87)

> > 
> > (I think that some pervert at Commonwealth Edison knows that a lot of

How about using surge protectors?, do those do any good?                                                                                

cjdb@sphinx.uchicago.edu (Charles Blair) (08/27/87)

The last time this subject came up (though not specifically about
AT's), it seemed to be agreed that leaving one's computer on was a
good thing, for the drives especially, but that occasionally monitors
would catch fire. The reason, as I recall, would be that a defective
monitor with a short in it would set fire to the dust that accumulated
inside it. Now I'd love to leave my AT on forever, but can anyone
guarantee me that I won't fry the monitor, possibly causing damage to
other equipment in the office? (This would be a real problem if it
happened at night, when the machine would be unattended.)



-- 
Bitnet:	  	 lib.cb@uchicago.bitnet
Internet:      lib.cb@chip.uchicago.edu
uucp:	  ..!ihnp4!gargoyle!sphinx!cjdb

alang@masscomp.UUCP (Alan Groupe) (08/27/87)

I don't understand. Why not just leave the AT on and turn the *monitor*
off?

Alan Groupe

npollack@polyslo.UUCP (Neal Pollack) (08/28/87)

In article <2237@sphinx.uchicago.edu> cjdb@sphinx.UUCP (Charles Blair) writes:
>
>The last time this subject came up (though not specifically about
>AT's), it seemed to be agreed that leaving one's computer on was a
>good thing, for the drives especially, but that occasionally monitors
>would catch fire. The reason, as I recall, would be that a defective
>monitor with a short in it would set fire to the dust that accumulated
>inside it. Now I'd love to leave my AT on forever, but can anyone
>guarantee me that I won't fry the monitor, possibly causing damage to
>other equipment in the office

I am the one who posted the fire info a while back.
In our lab facility, we leave all the CPU's and disk systems running
along 24 hours a day.  We DO however Shut Off all the monitors.
We have IBM and Clone monitors, Tektronics, HP, and others, that all
have an On/ Off switch on the front.   In the morning we turn on the monitor,
and find the software still running fine.

If your monitors do not have a separate switch, look into a power strip,
accessory switch, switched cord or something.

I must admit that in sections of the Lab where we have DENSE numbers of
smoke detectors, we even leave some of the monitors running all the time.
On those, we run screensaving ball-bouncers so as not to burn images
into the screen.

I personally do not have a good answer about monitors. I understand
the disk, CPU and monitor technology.  I know that thermal shock does
no benefit to the monitor electronics.  I also have experienced
monitor flame-outs.   I guess we can assume that new CRT's (~$80)
are cheaper than new disk drives.   (Depending....)

I recommend leaving CPU's and Drives on all the time.
If no alarm system is available and you care about fire,
then turn the monitor off, and take a very small gamble on the
maintenance aspect.

Of course, this is just my opinion, take it for what it is not worth.
-- 
| Neal S. Pollack		|    ...!ihnp4!csun!polyslo!npollack	      |
| Computer Systems Lab		|    ...!{csustan,csun,sdsu}!polyslo!npollack |
| Cal Poly State Univ.		|    ...!ucbvax!voder!polyslo!npollack	      |
| San Luis Obispo, CA  93407	|    Voice: (805)-756-2147                    |

jons@islenet.UUCP (Jonathan Spangler) (08/28/87)

In article <2237@sphinx.uchicago.edu> cjdb@sphinx.UUCP (Charles Blair) writes:
>
>The last time this subject came up (though not specifically about
>AT's), it seemed to be agreed that leaving one's computer on was a
>good thing, for the drives especially, but that occasionally monitors
>would catch fire. The reason, as I recall, would be that a defective
>monitor with a short in it would set fire to the dust that accumulated
>inside it. Now I'd love to leave my AT on forever, but can anyone
>guarantee me that I won't fry the monitor, possibly causing damage to
>other equipment in the office? (This would be a real problem if it
>happened at night, when the machine would be unattended.)
>

We leave our AT file server, running Novell ANetWare 2.0a, on 24 hours/day, 
7 days a week. When not in the office, the monitor, of course, gets turned 
off. Have also put more than a surge protector on the machine, in the form 
of a voltage regulator. 

There was a fire in downtown Honolulu that caused the power to go out, but
beyond that, haven't had a problem since about May of this year. A surge 
protector will guard against a sudden spike in voltage, but does nothing
for brownouts. Hawaii has more low-power situations, so therefore, a regulator
would be more helpful.

Aloha,

-- 
Jonathan Spangler
UUCP:         {ihnp4,vortex,dual}!islenet!jons
OPUS/FIDONET: Sysop@12/6 (HTCS BBS)
CompuServe:   71560,322

dave@westmark.UUCP (Dave Levenson) (08/28/87)

In article <2237@sphinx.uchicago.edu>, cjdb@sphinx.uchicago.edu (Charles Blair) writes:
> ...  occasionally monitors
> would catch fire.
> ... Now I'd love to leave my AT on forever, but can anyone
> guarantee me that I won't fry the monitor...

My suggestion, if at all possible, is to leave the "System Unit"
powered up, but turn off your monitor.  This will save the phosphor,
and some electricity.  The expensive parts (hard disks) are kept in
good condition and at a relatively constant temperature.  The
monitor is less likely to be hurt by turning it on and off (no
moving parts) and won't ignite anything when off.

I leave my AT&T PC6300PLUS on continuously (UNIX likes it that way).
I leave the monitor on for most of the work-day, and whenever I
expect to be logging in soon again.  I turn the monitor off (leaving
everything else on) when I'm off premises.

Is this a reasonable compromise?
-- 
Dave Levenson
Westmark, Inc.		A node for news.
Warren, NJ USA
{rutgers | clyde | mtune | ihnp4}!westmark!dave

jvc@mirror.UUCP (08/31/87)

/* Written 11:49 am  Aug 17, 1987 by magore@watdcsu.UUCP in comp.sys.ibm.pc */
>... It's interesting to see
>what happens when a fan in a power supply passes it's MTBF and dies [ they
>must have clocks in them :) ] What happens next could be termed 
>"short term burn in" ... :)

At the last place I worked at I was responsible for 5 IBM XTs.  Four
of the XTs where used in the offices (8AM - 5PM) and where shut off
every night.  The other one was turned off only on weekends since
it was used in the manufacturing area which was open 24 hours a day.
I never had trouble with the four that were cycled daily (except for
the first month or two when we had several defective drives/boards
replaced) but one weekend the manufacturing XT was left on.  When
I came in on the followin Monday I discovered that the fan in the
power supplied had failed.  Three boards and one hard disk drive were
damaged as a result.

Seems rather risky leaving the machines on for extended periods of
time when unattended.  Also seems like a waste of electricity to
have the machine on for 24 hours a day if you're only going to use
it 9 hours a day.

jvc@mirror.tmc.com

asjoshi@phoenix.UUCP (09/01/87)

We have 2 XT's and 2 AT's in the lab I work in and they are on 24 hrs a day
and 7 days a week. So far (I have been here for 2 yrs) there have only been 
two crashes of the hard disk on one AT (both happened when we shifted it).
In fact we have more problems of people wiping the hard disk out entirely by
"mistake"

baron@transys.UUCP (09/02/87)

In article <2237@sphinx.uchicago.edu> cjdb@sphinx.UUCP (Charles Blair) writes:
>
>The last time this subject came up (though not specifically about
>AT's), it seemed to be agreed that leaving one's computer on was a
>good thing, for the drives especially, but that occasionally monitors
>would catch fire. The reason, as I recall, would be that a defective
>monitor with a short in it would set fire to the dust that accumulated
>inside it. Now I'd love to leave my AT on forever, but can anyone
>guarantee me that I won't fry the monitor, possibly causing damage to
>other equipment in the office? (This would be a real problem if it
>happened at night, when the machine would be unattended.)

	No statistics, just an example. Xenix site "transys" (our site)
	has been up and running 24 hours a day for over two years. Sometimes
	I turn the monitor off before leaving work but most of the time I do
	not. I also oversee nine other xenix machines throughout the country.
	All of them are left running 24 hours a day, seven days a week.

Joe Portman
V.P. Software Developement
TransSystems Incorporated
1280 116th Avenue NE
Bellevue WA 98009
1-206-453-5560
ihnp4!uw-beaver!tikal!transys!root