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billdeg
August 17th, 2008, 06:56 AM
It's been too long...I haven't had anything burst into flames in a while....

My Apple /// just about burst into flames...ah! Saved in the nick of time.

I am reading a message on this board with the Apple /// running in the background (I was stress testing it) and then I smell this ...smoke...like wood burning. oh man.

Fortunately I have a spare power supply, but I would just like to complement the designers of the Apple /// for making a metal power supply chassis that is separated from the mother board and disk drives. Another thing I noticed is that the computer continued to work even while the room filled with smoke and the top of the table surrounding the system is burned..

and now I have another project.

Followup: After taking the power supply out of the chassis, I determine that the capacitor (I believe) with 22 microfarad rating in position C4 split open and was burning. It still smells in the room, I hope it's not toxic.

Bill

mbbrutman
August 17th, 2008, 07:17 AM
Wow. Good save.

I never run my machines unless I am in the same room with them, but I have been thinking about dedicating an old machine as a server and the thought of a failure has crossed my mind a few times. I don't want to burn out good hardware on something silly, but I was more worried about component failure, not fire.


Mike

billdeg
August 17th, 2008, 07:26 AM
I have already replaced the power supply and I am in the room running a new stress test with the new power supply. I never leave a computer unattended in these situations. I am preparing for VCF East, and these machines will be powered on for many hours, that's not when you want to find out you have a problem!

Unknown_K
August 17th, 2008, 10:18 AM
I only run the vintage stuff when I am there to watch them, the only 24/7 machine in the house is an old dual ppro server. I have seen running machines blow a power supply and turn off, have yet to have anything burn in normal operation (just a couple items I hooked up incorrectly over the last 20 years).

Do you guys have smoke alarms in your work areas and a good electronics rated fire extinguisher? I do.

per
August 17th, 2008, 11:15 AM
A friend of mine found her VGA monitor in flames, but I personally have'nt seen anything fry up like your apple /// PSU did. Glad my XT still works without troubble.

paul
August 17th, 2008, 02:49 PM
Given the nature of switching power supplies with electrolytic caps sitting on a high-voltage line-side DC bus the chance of a failure is only a matter of time, with hopefully the fuse being the only casualty. The problem is the current going into the supply may not be much more in failure modes than it is in normal operation.

It would be useful for all of us if we created a database of repair parts for the more common switch mode power supplies. I plan on replacing the main caps inside my IBM PC and AT supplies in the next year.

Druid6900
August 17th, 2008, 02:59 PM
It still smells in the room, I hope it's not toxic.

Bill

Aluminum oxide is the main ingredient, I believe, so, fairly, but not fatally.

Not like when your Northstar Processor boards both caught on fire and melted into two blobs of G10 epoxy LOL (just kidding).

billdeg
August 17th, 2008, 06:15 PM
lol

bd

mwillegal
August 20th, 2008, 04:07 AM
Even new stuff flames up from time to time. One typical case I'm aware of, involved electrolytic caps being installed backward due to process problems at the factory.

Regards,
Mike Willegal

vbriel
August 20th, 2008, 04:30 PM
LOL Bill,

You know that every year a computer smokes at the VCF East show. Now what are we going to do? You could have put a hex on the whole show now!

Vince

billdeg
August 20th, 2008, 07:12 PM
Let's just hope it's not mine...that's why I was doing the burn in. Here is a list of my vcf E exhibit as of today, given no hardware issues.

Apple II (a 1977-78 setup running a BASIC demo of some kind)
Apple /// (with Profile HD, running a Business BASIC or Pascal /// demo)
Sage II (running p-UCSD pascal demo) and maybe a line printer or IEEE Harddrive
CBM SuperPet (with D9090, 8050 drives and 8023 printer. Waterloo pascal demo)

I don't need any more hardware problems....We're expecting our third child (due Oct 1), my computer history class at the U of Del starts Sept 3, and I am also helping with the InfoAge Museum launch (IBM Model "A" PC 5150 exhibit).

What do you think of the name Vic if it's a boy?

Bill

barythrin
August 21st, 2008, 02:47 PM
lol sure, or Lisa if it's a girl. So.. OT since the newborn isn't obsolete but congrats ;o)

Druid6900
August 21st, 2008, 08:02 PM
We're expecting our third child (due Oct 1)
Bill

They know what causes that now :)

Congratulations on the forthcoming begot.

tezza
August 21st, 2008, 09:02 PM
I don't need any more hardware problems....

I hear you! :) Unfortunately "Vintage Computers" and "Hardware Problems" seem to go together like Ying and Yang.

Still , I suppose reparing the old beasts is just another way to enjoy them. I enjoy the sasifaction of fixing things but I always have the disturbing thought that if I stuff it up, then I can't just go down to the store to buy another.

On the other hand, if things are not working anyway, what have you got to lose?

Tez