How my 486 Tower died today

I thought I saw this the other day--in this group--but I'd like to share how my 10+ year old 486 tower I built from scratch died. It unexpectedly turned on by itself, and kept cycling (Windows XP logo would show, then it would reboot). Finally, I turned off the power from behind the machine using the toggle switch. I heard a click, no smoke, but after that the system was dead. Of course it must be a power supply problem, but it was funny how it turned on by itself. Luckily I don't use it anymore. Also I had it on UPS power so it was not a power surge that made it turn on.

I could replace the power supply and try to revive it, but I was going to toss it anyway.

RayLopez99 wrote:
I thought I saw this the other day--in this group--but I'd like to share how my 10+ year old 486 tower I built from scratch died. It unexpectedly turned on by itself, and kept cycling (Windows XP logo would show, then it would reboot). Finally, I turned off the power from behind the machine using the toggle switch. I heard a click, no smoke, but after that the system was dead. Of course it must be a power supply problem, but it was funny how it turned on by itself. Luckily I don't use it anymore. Also I had it on UPS power so it was not a power surge that made it turn on.

I could replace the power supply and try to revive it, but I was going to toss it anyway.

Could you find a power supply for it ?

It could have an AT supply, but I don't have any 486 machines
here to check.

The ATX supplies now, no longer have -5V on them, which
could impact a really old ATX system. If you had that situation, you
can use a 7905 regulator and the -12V rail, to make that voltage
available. For fun, I build up that circuit for my Slot 1 system,
just so the hardware monitor would read the correct voltage on
that rail. I thought maybe the Slot 1 system would need that
voltage, but it turned out it didn't need it. The hardware
monitor can still measure that rail though, which I thought
was a little strange. Why measure a voltage the machine
doesn't use ? It's a bit goofy.

Paul

On Feb 15, 2:07 pm, RayLopez99 wrote:
I thought I saw this the other day--in this group--but I'd like to share how my 10+ year old 486 tower I built from scratch died. It unexpectedly turned on by itself, and kept cycling (Windows XP logo would show, then it would reboot). Finally, I turned off the power from behind the machine using the toggle switch. I heard a click, no smoke, but after that the system was dead. Of course it must be a power supply problem, but it was funny how it turned on by itself. Luckily I don't use it anymore. Also I had it on UPS power so it was not a power surge that made it turn on.

I could replace the power supply and try to revive it, but I was going to toss it anyway.

486. Impressive (think I have one that still works. Old laptop
haven't tried in ages). And that is weird. Ought to be able to figure
a way to stick in a newer pwr supply...what, didn't they mainly change
over to a PWR-GOOD strobe on the ATX design, along with a newer
plug... Interesting things to do with crappy PS units included on a
bargain case only, say, that couldn't be seriously considered for much
else (than a landfill). Once had a 386 laptop that, when I took it
out of the satchel, looked like the screen melted - not physically,
but as if all the all screen pixels had opened up and spilled their
contents inside the screen. See, there are weird things, and then
there are just things that will stop a person in their tracks from
throwing money into a bottomless pit called computing.

On Saturday, February 16, 2013 1:48:31 AM UTC+2, Paul wrote:
RayLopez99 wrote:

I thought I saw this the other day--in this group--but I'd like to share how my 10+ year old 486 tower I built from scratch died. It unexpectedly turned on by itself, and kept cycling (Windows XP logo would show, then it would reboot). Finally, I turned off the power from behind the machine using the toggle switch. I heard a click, no smoke, but after that the system was dead. Of course it must be a power supply problem, but it was funny how it turned on by itself. Luckily I don't use it anymore. Also I had it on UPS power so it was not a power surge that made it turn on.



I could replace the power supply and try to revive it, but I was going to toss it anyway.



Could you find a power supply for it ?



It could have an AT supply, but I don't have any 486 machines

here to check.



The ATX supplies now, no longer have -5V on them, which

could impact a really old ATX system. If you had that situation, you

can use a 7905 regulator and the -12V rail, to make that voltage

available. For fun, I build up that circuit for my Slot 1 system,

just so the hardware monitor would read the correct voltage on

that rail. I thought maybe the Slot 1 system would need that

voltage, but it turned out it didn't need it. The hardware

monitor can still measure that rail though, which I thought

was a little strange. Why measure a voltage the machine

doesn't use ? It's a bit goofy.



Paul

It's a "Technoware" ATX 12V 2.2 compatible. Since I bought it in Greece, there's a chance it's counterfeit.

And from year 2006 says the sticker, meaning it's not original, and now that I think about it, I did change the original PS. So it lasted about 6 years, much shorter than the chips.

I see on Newegg the below PS, about $70 USD, that will probably fit, but then the question is: do I take a chance that perhaps the switch is bad? The pushbutton switch at the front of the case? If so, that needs to be replaced too. Might be cheaper to trash this system, which, as I say, I was only using as a backup PC to surf the net when my primary PC was unavailable.

RL


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4 out of 5 eggs (353) | Write a Review

In stock. Limit 5 per customer.

ATX12V v2.3
80 PLUS BRONZE Certified
100 - 240 V

RayLopez99 wrote:
On Saturday, February 16, 2013 1:48:31 AM UTC+2, Paul wrote:
RayLopez99 wrote:

I thought I saw this the other day--in this group--but I'd like to share how my 10+ year old 486 tower I built from scratch died. It unexpectedly turned on by itself, and kept cycling (Windows XP logo would show, then it would reboot). Finally, I turned off the power from behind the machine using the toggle switch. I heard a click, no smoke, but after that the system was dead. Of course it must be a power supply problem, but it was funny how it turned on by itself. Luckily I don't use it anymore. Also I had it on UPS power so it was not a power surge that made it turn on.
I could replace the power supply and try to revive it, but I was going to toss it anyway.


Could you find a power supply for it ?



It could have an AT supply, but I don't have any 486 machines

here to check.



The ATX supplies now, no longer have -5V on them, which

could impact a really old ATX system. If you had that situation, you

can use a 7905 regulator and the -12V rail, to make that voltage

available. For fun, I build up that circuit for my Slot 1 system,

just so the hardware monitor would read the correct voltage on

that rail. I thought maybe the Slot 1 system would need that

voltage, but it turned out it didn't need it. The hardware

monitor can still measure that rail though, which I thought

was a little strange. Why measure a voltage the machine

doesn't use ? It's a bit goofy.



Paul

It's a "Technoware" ATX 12V 2.2 compatible. Since I bought it in Greece, there's a chance it's counterfeit.

And from year 2006 says the sticker, meaning it's not original, and now that I think about it, I did change the original PS. So it lasted about 6 years, much shorter than the chips.

I see on Newegg the below PS, about $70 USD, that will probably fit, but then the question is: do I take a chance that perhaps the switch is bad? The pushbutton switch at the front of the case? If so, that needs to be replaced too. Might be cheaper to trash this system, which, as I say, I was only using as a backup PC to surf the net when my primary PC was unavailable.

RL


CORSAIR Builder Series CX600 600W ATX12V v2.3 80 PLUS BRONZE Certified Active PFC Power Supply
4 out of 5 eggs (353) | Write a Review

In stock. Limit 5 per customer.

ATX12V v2.3
80 PLUS BRONZE Certified
100 - 240 V

The Technoware I could find listed:

+3.3V - 28 A,
+5V - 38 A,
+12V1 - 26 A,
-12V - 0.8 A,
+5VSB - 0.6 A

which means it has no -5V. And then the Corsair you're looking at,
might be a replacement.

By selecting the Bronze, the efficiency isn't high enough to require
a two stage regulator. And that could be why the 3.3V and 5V amps
are a little higher than the average supply. Supplies with two
stage regulators (12V feeds a separate 3.3V/5V module), are not
really well matched to older computers. You want a 70% efficient
unit, where all rails come from a common transformer, as you
get a more generous combined rating that way. Modern supplies
have weak lower rails.

+3.3V @ 25A, +5V @ 25A, +12V @ 46A, -12V @ 0.8A, +5VSB @ 3.0A

On an older system, the 3.3V and 5V might be sourcing the majority of
the load. While the power supply has a 600W rating, in this case
the combined rail rating on the first two rails in the previous line,
is 130 watts. (I can't find another picture like this, and my eyes
can barely make out that figure.)

http://images17.newegg.com/is/image/newegg/17-139-028-Z05?$S640W$

Your 486 likely draws most of its power from the 130 watt combined
rating section. If I was working on your machine, I would verify
current flow with my clamp-on ammeter, before returning the unit
to you. I've had machines here, ancient relics, that draw around
150W (which would include a few hard drives), so it's getting a
bit close.

The 12V @ 46A rail hardly gets used. It might power the 12V rail
on your hard drives, at about 0.6 amps per drive. It runs the optical
drive. A few things like that. If you have an older video card, they
sometimes draw a bit of power from 12V as well. So the majority of
the supply rating is wasted, as the older systems just don't draw
on the 12V that much. Even an old Powmax with 12V @ 10A rating would do.

A little additional Googling, seems to show a Corsair V1 and V2 version
of CX600. And the contract manufacturer being used for one of
those is CWT (ChannelWell). Now, personally, I've had two
ChannelWell built supplies die on me, and I couldn't envision
me buying a third. So Corsair doesn't build the supply themselves,
and CWT does the contract. When it comes to gambling, the odds
are fixed in the house's favor, as they say...

There might be another Corsair product that isn't made by CWT, for
a few more dollars. Or, you could look for some ancient
design, that has the balance between rails set for the
lower rails.

This is what I used on my oldest system.

"Sparkle ATX-400PN-B204"
http://www.newegg.com/product/produc...82E16817103013

Pros: Doesn't seem to have PFC that I can tell. Means it won't fight
with my old UPS.
Cons: Not 80% efficient (warmer in summer).
Wire set is pretty limited. May need Y cables to finish your build.
Doesn't come with a power cord!

+3.3V @ 30A, +5V @ 28A, +12V1 @ 18A, +12V2 @ 18A,-12V @ 0.5A, +5VSB @ 2.0A

It's still not a "brutal" unit, such as some of the older ATX
supplies that could deliver 40A on the lower rails. But it's $40.
And it hasn't blown up (yet). Check the Newegg reviews for an
idea on failure rate.

"Temperature Range: Operating 0°C to +25° C on full load;
De-rate 2W/C from +25°C to +50°C."

That means, if you run the unit at 50°C, it becomes a 350W
supply instead of a 400W supply.

http://images17.newegg.com/is/image/newegg/17-103-013-S03?$S640W$

"Combined 3.3V and 5V load = 150W max"

That beats the value-level Corsair by 20W on the combined load.
The 12V portion of the supply won't feel much of a load. And
the total system power is unlikely to get close to 350W. Maybe
200W total if you had a few drives in there.

*******

For a "blast-from-the-past", companies like this built supplies
with pretty high ratings on the lower rails. I don't know if Zippy-Emacs
is still in business, but you'd get 3.3V @ 30A and 5V @ 45A. And the
design is old enough, it even has a minimum load rating. Looks
like Zippy-Emacs was acquired by Tyan, and this supply is around $300
now (hahaha). And they don't even list a combined rail spec (as
it is unlikely to supply 324W on those rails as a total).

http://www.bjorn3d.com/2006/10/zippy...-power-supply/

It takes a lot of time to track down reviews, find a picture
of the nameplate. As a lot of companies are so incompetent they
can't be bothered to show a proper picture of it. And then I'm
forced to squint at some low-res picture on Newegg.

Paul

On 2/15/2013 1:07 PM, RayLopez99 wrote:
I thoughtplace the power supply and try to revive it, but I was going to toss it anyway.




Yeah right

XP on a 486, nice try

On Feb 18, 10:53 am, philo wrote:
On 2/15/2013 1:07 PM, RayLopez99 wrote:

I thoughtplace the power supply and try to revive it, but I was going to toss it anyway.

Yeah right

XP on a 486, nice try

Did it on a IBM laptop 486-something couldn't have been 40Mhz. Guess
you've never run all the modules for a program called Patience w/out a
HD from a 360K floppy inside metal lunchbox computer with a carrying
handle and a RF modulator for seeing it in all its glory from a 5"
portable b&w teevee.

On Saturday, February 16, 2013 12:37:26 AM UTC+5:30, RayLopez99 wrote:
I thought I saw this the other day--in this group--but I'd like to share how my 10+ year old 486 tower I built from scratch died. It unexpectedly turned on by itself, and kept cycling (Windows XP logo would show, then it would reboot). Finally, I turned off the power from behind the machine using the toggle switch. I heard a click, no smoke, but after that the system was dead. Of course it must be a power supply problem, but it was funny how it turned on by itself. Luckily I don't use it anymore. Also I had it on UPS power so it was not a power surge that made it turn on. I could replace the power supply and try to revive it, but I was going to toss it anyway.

On 2/18/2013 4:01 PM, Flasherly wrote:
On Feb 18, 10:53 am, philo wrote:
On 2/15/2013 1:07 PM, RayLopez99 wrote:

I thoughtplace the power supply and try to revive it, but I was going to toss it anyway.

Yeah right

XP on a 486, nice try

Did it on a IBM laptop 486-something couldn't have been 40Mhz. Guess
you've never run all the modules for a program called Patience w/out a
HD from a 360K floppy inside metal lunchbox computer with a carrying
handle and a RF modulator for seeing it in all its glory from a 5"
portable b&w teevee.



I've been around for a long time.

In school I started out in the punch card days of the late 60's
writing FORTRAN programs.
In the late 70's built a computer to program EPROMS.

Do a lot of experimenting with obsolete machines.

Though it's not impossible to hack XP in such a way as to run it on a
486, I seriously doubt if the OP "just installed it" on a 486.

My "biggest" experiment in futility was hacking win98 to run on a 386.

Basically I turned it back to win95 to do so.

On Monday, February 18, 2013 5:53:19 PM UTC+2, philo wrote:
Yeah right



XP on a 486, nice try

Why is that weird?

RL