csrobe@ICASE.EDU (Charles S. [Chip] Roberson) (04/24/89)
WARNING: Long message follows, but please read it, I need help!
Many of you probably remember me from the summer of 1987 when my
Supra 20meg went unreliable on me -- it would sporadically speed
up and then park itself. I spent from June of 87 until
May of 88 trying to get it fixed. They replaced it in May. It
then sat in storage for 6 months until I moved in October. Recently
my new one has been acting up.
The original one had two problems: 1) the speeding up and 2) the
parking. The problem manifested itself on a hot June summer day
and persisted for some time. Since I wasn't sure if I had one or
two problems I don't remember details that well. However, I do
remember beng able to reproduce some sympton both with my HD
disconnected from my ST and with the HD standing alone in the store
where I bought it. After 10 months they finally replaced it and I
thought my troubles were over.
As I said my HD was unused for all of the Summer of 1988. It served
me fairly well through winter but I did notice an occassional parking.
I don't remember how many times it occured but it was rare enough
that I didn't want to start another round with Supra and ACA (the
retailer). Anyway, as the temperature is getting warmer and warmer
the problem is showing up more. Today, was the hottest day so far
this year and it was the worst day for my HD -- it was basically
unusable. [Now, I have to put in a caveat here -- I did take the
cover off to look inside for part numbers and I picked the HD up
for the first time in several months. This may have been a trigger.]
Anyway, the HD is parking itself -- it does NOT exhibit the symptom
of the sporadic speed up. During normal operation the HD just decides
that it doesn't want to spin any more and spins down. The busy light
will flash for a while and then stops. Sometimes it will spin back
up just to park itself again. Sometimes it will start to spin back up
but park itself before it gets to full speed. I've tried turning it
off and turning it back on with no consistent effect -- sometimes
it starts as it should, othertimes, it just sits there, not spinning.
The busy light flashes at about 2 flashes per second and sometimes
becomes erradic. Sometimes it just stops flashing all together.
After it has stopped flashing you will hear an occassional tick
or buzz and either the hard disk will attempt a spin up or the
busy light will start to flash irregularly.
All of this happened with:
o the HD connected to ST
o the HD disconnected from the ST
o the HD disconnected from the ST and the cover off to help
ventilation.
Currently I suspect that the drive has one of the three problems:
1) It is extremely sensitive to either heat, humidity, or both.
2) It has a loose connection or my ST likes to fry some part of
Supra drives to make the park themselves.
3) or, my cordless phone is messing with my HD as well as my phone
line.
I know that last one sounds preposterous, but I'm not beyond doubting
it. I have an AT&T cordless phone which goes crazy at various times
according to what is being displayed on the screen. For example, a
window could open or I could be returning from gulam and my hand set
will start chattering with all kinds of noise. Other times, my
hand set can be off and my base unit will start sending trash through
my phone line and completely mung a connection. Is there anyway that
radio frequencies could cause my HD to act in this fashion?
I am going to move my phone out of the room and see if that has any
effect. I know it will at least stop 1 aggravation -- the chattering
handset!
Anyway, my strongest suspect is heat -- the HD has NO fan!
So I am looking into getting and ICD FAST hard drive case with
the cooling fan and other nice features. Can I rip the following
hardware out of my Supra case and shove it into an ICD? If I
eventually want to add a second drive can I? What kind is necessary?
Hard Disk Type: Miniscribe 8425s
Controller Type: Miniscribe 8425
Well that's basically my problem. Can anybody out there share any
speculations on what is causing the problem and propose some solutions.
Will I be wasting my money (what precious little is left) by getting
the ICD FAST hard drive case? As you can tell, I am not an electrical
engineer so I have to rely on those of you who are. How should I
attack this problem?
Please can anybody help me?
Here are some specs from the Supra format utility (supfmt.prg):
SPECIFICATIONS:
Heads: 4
Cylinders: 612
Sectors per track: 17
Interleave: 1
Reduced write: 612
Write pre-comp: 612
Landing zone: 4
Step pulse rate: 2
Reserved tracks: 40
Map bad sectors: NO
Removable Media: OFF
Forced partitions: NO
I thought somebody might find these useful. Anybody willing to add
some meaning to some of these specs, like "reduced write" and "write
pre-comp"?
Again, I would like to appologize for the length of this article
but I really need help. All comments will be GREATLY appreciated!
Thanks,
-c
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|Charles S. Roberson ARPANET: csrobe@icase.edu |
|Dept. of Comp. Sci. csrobe@cs.wm.edu |
|College of William and Mary BITNET: $csrobe@wmmvs.bitnet |
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| (804) 229-5530 COMING SOON: csr@endor.uucp |
+-------------------------------------------------------------------------+al@tolerant.UUCP (Albert Palmer) (04/25/89)
I have had very bad luck with the Miniscribe in the Supra 20. The first thing you need to do is call Supra and order a fan for your drive. Sometime in the last year Supra started using a fan in their 20meg. The fan moves alot of air. Sounds like a jet taking off. You can slow it down by putting a resistor in line with the fan. I have a 50 ohm in mine, but I'm using a Quantum 80 and it puts out alot less heat. You might try something around 10 ohms and 2 watts. Hope this helps. al palmer
Captain-Magic@cup.portal.com (Randy Captain-Magic Holcomb) (04/26/89)
It sounds like your MiniScribe 8425 is getting fits in the heat. I had (until recently) a exact configuration like you, and it did get very hot here last summer, but I did not have a parking problem or any of the problems you are mentioning. You may want to contact Miniscribe and ask them abot temperature tolerances and the like; I don't know if changing host software or the host adaptor board will cure your problems. Randy Holcomb Captain-Magic@cup.portal.com CIS: 70621,50 GEnie: RANDYHOLCOMB Bix: rholcomb Delphi: RANDYH
pvf@bridge2.3Com.Com (Paul V. Fries) (04/27/89)
In article <4111@tolerant.UUCP> al@tolerant.UUCP (Albert Palmer) writes: >I have had very bad luck with the Miniscribe in the Supra 20. The first >thing you need to do is call Supra and order a fan for your drive. >Sometime in the last year Supra started using a fan in their 20meg. >The fan moves alot of air.... Funny you should mention this. I have had a Supra 20M for several years now. One of the first things I noticed was that the thing ran HOT. I put a fan in it about 3 days after I bought it. I have had no real problems with the machine since. I say no real problems because I did have a problem after moving the machine (i.e. disconnecting the hard drive cable) several times. The whole thing became quite flaky. I tried reformatting and everything, but the results were inconsistent and not very reproduceable. As the only thing I had recently done to the machine that seemed related to the new failures was moving it, I looked inside the shell of the connector body and found the WORST solder joints I have ever seen. At least half of the joints were obviously cold-soldered. I resoldered all the wires in that connector. It was simple, just heat and feed a little more solder on the joint. It has worked perfectly ever since. Overall, my rating of the Supra 20M is 7 out of 10. I was really disappointed that there was no fan, and the connector problem was just plain unacceptable. But, with these items cleared-up, the thing works fine. PS -- I think I have seen later models of the Supra drives with molded connectors, so maybe they learned a lesson there.