horn@cat19.cs.wisc.edu (Mark Horn) (05/09/90)
Well, my machine, harier, has been upgraded from 1Meg to 2Meg memory and
MGR runs without the disk constantly seeking. A performance improvement,
indeed. I thank the person (I can't remember who it was) who posted the
experiences and problems with this upgrade. The instructions were very clear
and I'm liking life with 2Meg!!
However I wish to warn those of you out there wishing to do this upgrade.
I have a 40Meg Half-Height HD in my machine. With the 7300 power supply, it
ran perfectly. I only had one crash and that was not because of the power
supply (it was because I was stupid). Anyway, after I put in the second Meg
I noticed that I couldn't boot from my HD from time to time. It was very
sporadic. I could boot from floppy easily enough. Coincidentally, this was
at the same time that Thad Floryan was posting information about how
seagate drives can have this problem (My drive is a seagate st251-1). Well, I
just attributed it to this problem, and left it be. Being, as I'm stupid,
I didn't make a backup. I didn't have time for that.
Anyway, it got to the point where no matter how hard I tried the drive would
not boot. Well, I was not happy about this. I then thought that Thad's
assessment of his experiences with seagate drives had shown itself in my
poor machine. So, I reconciled it with myself that I had to get a new HD.
But I wanted to try and boot just once more so that I could back it up.
I figured I'd stick it in a machine with a 3b1 power supply and see if that
wouldn't jump-start my drive so that I could back it up.
Well, what do you know, but it worked! I quickly did a back up and decided to
see if it was luck or what. Nope. I powered down and booted up at will without
a glitch. Then it hit me: in order to support the extra meg of memory I needed
the 3b1 power supply! Sure enough, I replaced my 7300 power supply with the
3b1 power supply that I never got around to installing, and I've been running
fine ever since.
So, after all of that, here's my warning: If you plan to do this upgrade, make
sure you have a 3b1 power supply, or you may have trouble booting.
FYI,
- sparkie
--
___ ___ ___ ___ _ _ _ ___
/ __\| . \/ . \| . \| |/ /|_|| _ | "Mothers Against Skunks Driving...
\___\| __/| || _ /| < | || _[ ...because stinking and driving don't mix"
\___/|_| |_|_||_|\\|_|\_\|_||___| - heard on a madison radio station
ARPA: harier!sparkie@cs.wisc.edu, sparkie@uhura.cs.wisc.edu
UUCP: ...{harvard|rutgers|ucbvax}!uwvax!astroatc!nicmad!madnix!harier!sparkiescj@pandora.bellcore.com (Steve Johnson) (05/09/90)
In article <4830@daffy.cs.wisc.edu> horn@cat19.cs.wisc.edu (Mark Horn) writes: >the 3b1 power supply! Sure enough, I replaced my 7300 power supply with the >3b1 power supply that I never got around to installing, and I've been running >fine ever since. > >So, after all of that, here's my warning: If you plan to do this upgrade, make >sure you have a 3b1 power supply, or you may have trouble booting. > >FYI, >- sparkie >-- Upgrading a 7300 PS is a good idea (if you have a 3b1 PS B^) *but* what sparkie has seen *may* have been the infamous power supply solder joint failure. Seems that some, if not all hard drives powered by a 7300 PS (that is, through the motherboard traces) draw enough power that the solder joints on either the power supply side or the motherboard side of the power supply header (that set of 16-18 STIFF wires going from the power supply to the motherboard on the right side of your machine) get warm. *very warm!* This heat is enough that, in some cases and over time, an increase in oxidation and/or an actual melt of the solder occurs. The combination of the heat, oxidation and continued neglect (ask me, the man who owns one!) creates a self-feeding cycle that causes more heat, etc. Which eventually gave me exactly the symptoms that sparkie described (HD won't boot). In my case the plastic connector was burnt badly as well, so I now have all those wires soldered directly to the PS and I check the quality of those new solder joints and the old motherboard solder joints regularly. As was posted about 1 1/2 years ago, check that PS hardware regularly! Include the check in your semi-annual dust bunny roundup.