OT: killed my computer

On Mon, 1 Dec 2008 19:32:22 -0500, the infamous "Buerste" scrawled the following:

Anyone running a computer nowadays (given the quantity of electrical noise and fluctuation on the lines) which is _not_ on a UPS is a fool.

I paid $150 for my TrippLite Internet Office UPS ten years ago and I've put a battery in it ($17) since then. I bought the UPS after having lost the best sales pitch I'd ever written to a one second glitch in the CA power service. I vowed "never again!", and if the guy who caused the glitch had been in my room at the time, I'd have taken him outside and drawn and quartered him right then and there.

I found a UPS for my entertainment system (stereo/dvd/vcr/sat box then) at Staples for $30 on sale. UPSes are cheap enough now, and since the power line noise just sucks today, they're a necessity.

-- The only difference between a rut and a grave...is in their dimensions. -- Ellen Glasglow

Larry After you cooled down were you able to rewrite your sales pitch? I have had to recreate artwork done in a CAD program I use because I forgot to save it as I went along and had my computer freeze. I found it easier to do the second time but not nearly as enjoyable. Steve

Notice I mention an "Active" UPS. That way the computer is always running on the battery and inverter circuitry. The passive UPSs switch to battery when they detect an out of parameter condition. BIG difference!

On Tue, 2 Dec 2008 08:45:06 -0600, the infamous "Up North" scrawled the following:

Yeah, but it wasn't quite the same afterward. Anger and creative inspiration do _not_ play nicely together, so some of my most creative thoughts didn't make it back on paper. I did get the new client, but I had to work at it. I had been careful to save most other documents every few minutes, but you know how it is when you're inspired. You forget those silly things. IAC, that was the last straw. If I'd had a red button in front of me right then, San Diego Gouge and Extorsion would have been nuked...once the power was back on.

I haven't been without a UPS since.

-- The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man. -- George Bernard Shaw

"active" - better known in the computer and power conditioning world as "dual conversion"

"Line interactive" is one step down but adequate.

Standby is bottom of the line - it has a "switching time"

Anything that the $500 UPS might accomplish is supposed to be done even better by the computer's power supply. After all, what does that $500 UPS do? Its power supply simply does same as a computer power supply does, then creates what is often electricity dirtier than found on AC mains. Well, yes, the $500 UPS is cleaner than the computer grade (sub $100) UPS. But that makes no difference to a computer. Some of the dirtiest power comes from a computer grade UPS when in battery backup mode. Dirty electricity that must be completely irrelevant to any computer because of what all computer power supplies did even 30 years ago.

That UPS accomplishes nothing for the OP's problems. And if 'dirty' electricity was causing power supply failure, well, the market is chock full of power supplies missing essential functions. Why? Because many if not most computer assemblers don't even know how electricity works. That creates a market for power supplies (missing essential functions) that sell for less money AND have higher profit margins.

Power supplies marketed to the electrically naive would then fail more often. So what do the naive then do? Buy a $500 UPS instead of spending $25 more for the power supply? That bean counter's mistake is why some recommend unnecessary $500 UPSes.

TO do any good it needs to be a double conversion ups, not one of the little cheap S-UPS's.. Surges pass right through those

jk

Karl you are doing better than I am. I bought a pair of 512M chips to take my

2001 vintage box up to 1G. Got a decent deal from pcwonderinc.com that sells under the name pcesupply on ebay.

Yanked the two 256M chips from the two slots, put in the two 512M chips and fired it up.

Sniff, sniff, I smell smoke. Pull the cord while watching with a flashlight one of the surface mount chips slide off the PC133 memory.

Pull the card out, ouch, warm, very warm. Look at keying, how did I get that to fit? Oh well, I blew it. Might as well go for broke, put one of the 256M chips in (properly) and fired the box up. Tested 768M and windows boots!

Contacted pcesupply and asked price for one telling them why I need it. Left good feedback with comment that the chip I didn't put in backwards worked just fine.

They responded, 9 bucks delivered and we are glad you mother board is fine, we just sent you a paypal request to do the deal. That took them about 15 minutes to get back to me from a Ebay contact the seller entry.

I've been installing memory back to DIP packages and have even wire wrapped my own memory expansion card to save money back when memory was expensive. I'm surprised I didn't fry the mobo. Likely that crappy power supply in my HP pavilion didn't have the arse to kill it.

Wes

own memory

arse to kill

Power supplies must contain foldback current limiting so that a shorted power supply remains undamaged. Apparently that foldback limiting also protected the motherboard.

Most likely location for damage would have been where memory slot connects to the power plane (inside motherboard). Only that slot would have failed. Apparently that connection did not fry. HP pavilion power supply apparently performed as required by industry standards. Apparently the power connection to that memory slot was robust (or may be charred but still conductive).

How much current should a wire wrap conduct without damage? Something like 30 amps. An indication of why a shorted memory might cause foldback current limiting without motherboard damage.

One would expect a power supply designed properly to fold back but these things are cheapest bidder type stuff. The first powersupply lasted 4 months and HP would not send me a new one, I had to send the box back at their expense as in they sent me packaging and prepayed return. Idiots. The replacement must be a bit better.

I'm still shocked this mobo survived this. Still using the PC.

Well, I'm not sure but the kynar covered wires would go before the square pins.

This wasn't wire wrapped that was back in the TI 99/4a days.

Wes

Sorry, but as a professional I have to dissagree with you. ONE of the major problems affecting computers is HARMONICS. ONLY a dual conversion can protect bothe the computer and other devices downstream from Harmonics. Switcher power supplies can cause harmonics. Power lines can amplify them.

A separately generated power supply in a good dual conversion UPS is CLEANER than the vast majority of the North American powwer grid.

Power ripple is a major contribution to power supply failure - that is otherwise known as "noise"

And I have had to replace some VERY EXPENSIVE designer PC power supplies. Like $400 power supplies (crazy, eh?)

On Tue, 2 Dec 2008 13:16:03 -0500, the infamous "Buerste" scrawled the following:

You 'splain me, Tawmy? (No info was found online during a quick googling for it.)

I've always had passives and they've worked fine. Who makes actives and what's the price differential?

-- The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man. -- George Bernard Shaw

Obvioius was that a motherboard has no wire wraps. But with kynar wire experience and that posted ampere number, then you can appreciate how much current would be required to also harm PC traces inside that motherboard. IOW why a motherboard trace feeding a memory slot could short so much current and not be damaged.

Brand name computer power supplies meet ATX standards as did power supplies 30 and 40 years ago. Foldback current limiting would be necessary for a long list of reasons including proper operation of the overvoltage protection circuits, the 'shorting all outputs together' test with no damage, and basic fire safety. An HP supply will most certainly contain foldback current limiting which explains why a shorted memory card did not cause motherboard PC trace damage.

Had that short been via a data or address trace, well, damage would have been probable. Current for Kynar wire puts into perspective why a shorted power supply did not cause motherboard damage.

Sorry, but as a professional I have to disagree with you. :)

Harmonics is NOT the big problem it is often made out to be.

A DC ups will only protect you from voltage harmonics, and even then, if the major source of harmonic currents are on the downstream side, they can only do so much.

And if we are talking about a standard (Cheap ass) non power factor corrected PC power supply, it can actually be happier with a voltage input that looks more like a square wave. [Lots of 3rd & 5th]

Power lines do NOT amplify harmonics. They are subject to ohms law just like any other electrical circuits. THe power lines have different impedance at different frequencies, but most harmonic sources act more like constant current sources, than constant voltage sources.

Not generally. Failures are due usually to increases in voltage either long term or momentary (surges). Noise is generally considered as a high frequency (relative to the power line) phenomena, and isn't generally considered as a cause of failures.

jk

WHat he defines as an "active" UPS is more commonly referred to as a "double conversion" ups.

In a double conversion UPS all of the power is converted to DC, to feed the DC bus and charge the batteries. THe DC is then turned into (via an inverter) AC that is completely separate from your AC line. When your input goes away, you just continue , but start discharging your battery.

THe other type of ups, feeds input power straight out to the load, and also charges a battery. WHen it senses a power problem, it starts the inverter and then uses a relay to swap the output to it. Not a big deal if the problem is a slow rise or fall in the voltage. But a surge, or a total outage,[or other high speed events] which travel at effectively the speed of light, reach your power supply before the relay can do any thing about them.

OTOH, they are MUCH cheaper.

[I have also had the fun of listening to them oscillate in a server room. As they decided the power was OK again, they all [1 SUPS per server] switched back at the same time [Factory default]. THis caused enough of a sag [when the line voltage was a little low, while doing a generator test] that they all switched back to battery, but then the power was ok again, so they all switch back to the line.....and so on and so on.]

jk

An "Uh oh!!" moment. You go to High Alert, your gut says that you have to do something, FAST!, but you don't know what to do! But don't do more harm than good! What to do, what to do ...??

Bob

That last bit is why once a site is big enough to have a "server room" of any consequence, the little individual UPSes need to go the way of the dodo and be replaced by larger "real" UPSes. When you get big enough you have multiple huge UPSes, battery rooms, static transfer switches, etc. and "real" power management.

I just buy "better" power supplies. We have fairly good power here and most of my customers don't use UPSs except on some servers.

Okay, I get your comparison. Sometimes I'm dense.

Looking at the stick with the two keying notches to the left, counting left to right, chip

4 fell off, the reverse side has chip opposite showing signs of slippage.

When I upgrade the hard drive I'll get a look at the back side of the mother board. Been a long time since I failed smoke check on electronics. Last week when I decided to do an OS reinstall, add ram and such, I ordered ram, HDD, and a new power supply. I've found life is so much better if you just use a new drive and keep the old one handy in case you didn't get a copy of everything that matters. I ordered the new power supply since the fan in this one has been dead for over a year an aux case, stuck to the side of the PS has been handling cooling for a year or so. The PS and HD showed up today. Hoped the UPS driver liked the hike to my house. He didn't want to try my snowy driveway with his truck ;)

There is some serious current availability to a chip slot on these PC's. It didn't take more than a few seconds to desolder the chip.

Wes