neumann@sun.udel.edu (Brian R. Neumann) (06/29/90)
I have been having numerous problems with my ST251-1 hard drive almost the enitre time I've owned it. Errors seem to crop up daily with my files, making them useless. Norton Utilities finds about 5 errors a day. After reformatting the drive all errors were gone until I copied more files to it. After looking more carefully, it appears that unused sectors of the disk never have errors. I suspect that the reason only used sectors are damaged is due to heat problems. Can anyone confirm this? I have installed the drive in a relatively small computer (Epson Apex) without it's own power supply. Could it be that it also needs it's own supply? Brian BTW, I was having similar problems when I bought an ST251 last August, and Hard Drives Internat'l replaced it no problem. Since this problem is still occuring, I assume that the drives were both physically OK.
baer@uwovax.uwo.ca (06/30/90)
Perhaps of no immediate use to the individual who suspects overheating on his hard drive, I thought I'd relay some experiences I have been having with my AST Premium 286. AST's machine is configured with memory on a separate proprietary board (beside the motherboard), and I've installed a 2nd "Fastram" card to bring my system memory to 4 mB. The proprietary memory boards must be installed side by side (one can't space them out across 16-bit slots -- they have special slots). Now, about 2 months ago I encountered massive disk errors -- culminating in my inability to read from my 72mB micropolis drive at all. Scary. I think I've tracked down the source of the problem, though: I had stacked papers and stuff on top of the case of my machine, and when I took them off, the metal case was quite warm to the touch. Now I was very careful not to put any junk near the power supply fan (at least 3-4" of open space to the back of my machine), but apparently this was not enough (the boards generated a fair amount of heat, it appears). The problem also occurred when I had left the central A/C in my house off (the ambient room temp. at the time was about 78-80 degrees F). Since then, the problem has occurred again once (not papers stacked on top of the machine but ambient room temp above 78 degrees F) -- again, the portion of the case just above the memory cards + motherboard got a bit warm [the machine had been on for 4-5 hours]. I seem to be able to avoid the problem by placing a small room fan near the machine, and I can always avoid the problem by turning the A/C on and keeping the room temp. in the mid 70s or lower. I believe it was the disk controller on the motherboard of my AST which was giving me problems. Implications of my experiences: if my assumptions are correct, machines crammed with extra boards *might* generate heat in unexpected places, and this might affect individuals' plans to run their machines "turned on their sides". This might also have implications for the whole "is it a good idea to leave the machine turned on overnight?" debate -- the answer to this question might depend on the heat-generating characteristics of the machine & the boards which have been installed. Finally, I suspect there's a message regarding add-on boards here: if possible, avoid adjacent slots for any board which might generate heat (obviously, this advice is of no use to someone who comes close to filling all available slots). Comments on my comments are welcome. I remain willing to be corrected with respect to any of my observations or assumptions. - Doug Baer Sociology University of Western Ontario <BAER@UWOVAX.UWO.CA> .
dhiman@motcid.UUCP (Ravinder Dhiman) (07/01/90)
baer@uwovax.uwo.ca writes: >Perhaps of no immediate use to the individual who suspects overheating >on his hard drive, I thought I'd relay some experiences I have been >having with my AST Premium 286. AST's machine is configured with [extra text deleted] >I had stacked papers and stuff on top of the case of my machine, and >when I took them off, the metal case was quite warm to the touch. >Now I was very careful not to put any junk near the power supply fan >(at least 3-4" of open space to the back of my machine), but apparently >this was not enough (the boards generated a fair amount of heat, it >appears). The problem also occurred when I had left the central A/C >in my house off (the ambient room temp. at the time was about 78-80 >degrees F). Since then, the problem has occurred again once (not [text deleted] >a small room fan near the machine, and I can always avoid the problem >by turning the A/C on and keeping the room temp. in the mid 70s or >lower. [text deleted] > Implications of my experiences: if my assumptions are correct, >machines crammed with extra boards *might* generate heat in unexpected >places, and this might affect individuals' plans to run their machines >"turned on their sides". This might also have implications for the >whole "is it a good idea to leave the machine turned on overnight?" >debate -- the answer to this question might depend on the heat-generating >characteristics of the machine & the boards which have been installed. >Finally, I suspect there's a message regarding add-on boards here: if >possible, avoid adjacent slots for any board which might generate heat >(obviously, this advice is of no use to someone who comes close to >filling all available slots). > Comments on my comments are welcome. I remain willing to be >corrected with respect to any of my observations or assumptions. > - Doug Baer > Sociology > University of Western Ontario <BAER@UWOVAX.UWO.CA> >. You have made some interesting points above. I think you have generally made some good assumptions, although you made no mention of whether you have run any other disk sanity checks on your hard drive. I have an XT just about loaded to the "gills" with add-in cards (one of them a voice-mail card) and I have 2 hard drives installed. I regularly leave my machine turned on all day in above 80 degree F tempratures without it encountering problems. Does your hard drive sit near your memory boards? If so, move it to a different slot. Also, do your power supply fans (some supplies contain more than one fan) have a lot of dust build-up? If so, try to clean them. Dirty fans are less efficient at moving air than clean ones. Given the problems you have encountered, I would go with your comments and: 1.) Leave AT least 3 to 6 inches of clear space at the back end of the machine, and 2.) Keep a fan on to provide the machine with good air flow. Last thoughts: I am new to this netnews stuff, so If I've made any mistakes, sorry. Also the usual about these being my opinions, etc. Ravi Dhiman Motorola Cellular Infrastructure Div. Arlington Heights, IL, USA.
gordon@eecea.eece.ksu.edu (Dwight Gordon) (07/01/90)
I missed the initial thread of this discussion, so please be somewhat
forgiving if I'm mentioning something that has already been discussed.
I too have an XT-class machine nearly "loaded to the gills" with
floppies (2in and 2out), hard drives (2in), and cards. My unit was
situated horizontally (standard desktop configuration) with my
monitor on top. The two hard drives (HH) were stacked on the left
and the two floppies (HH internal) were stacked on the right.
Initial Observations -
1. My lower hard drive (system drive) would sometimes fail. This
failure only happened after the system had been running for a "long"
period of time. To "repair" it required that I turn the unit off
and on (a warm-boot didn't work!?!).
2. The monitor base was something of an effective insulator. The
case under the monitor (which just happened to be at the location of
the hard drives) was noticeably warm to the touch.
3. My hard drives (ST225s) would sometimes "squeal." It sounded
like a questionably-lubricated bearing on the spindle motor.
I suspected thermal problems and changed the location of the hard drives
and the floppies (internal) by placing the hard drives on the lower
positions of the drive bays (horizontally) with the floppies above
them. The floppies have far less mass and allow some air motion.
New observations-
1. In the 6-weeks since I made this change the hard drive "failure"
has not been repeated. It previously occured at least once each
day.
2. The system case under the monitor is no longer significantly
warmer than the rest of the case.
3. I've noticed no significant increase in failures with regard to
the floppies sitting above the hard drives. However, I don't use
those floppies that often.
4. My hard drive "squeal" has gone away (at least for the moment :-).
- Dwight -
Dwight W. Gordon, Ph.D. | 913-532-5600 | gordon@eecea.eece.ksu.edu
Electrical & Computer Engineering Department | dwgordon@ksuvm.bitnet
Kansas State University - Durland Hall | rutgers!ksuvax1!eecea!gordon
Manhattan, KS 66506 | {pyramid,ucsd}!ncr-sd!ncrwic!ksuvax1!eecea!gordon