Shorted Computer Power Supply

"Connected a drve with the power supply on."

With the supply connected to the motherboiard as well? If so, the odds of having damaged other components connected to the power supply are so high that the power supply is the least of your worries.

Spend a few dollars on a new power supply - DIY repairs are not something a novice is likely to be successful with.

John

ATX Power Supply Schematic

-- # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060 # 831-336-2558 #

snipped-for-privacy@cruzio.com # AE6KS

Hi Jeff,

Thanks for your link ATX Power Supply Schematic

Could not find any schematic for ilssan model ISP 120SI

When I searched used

but also found No ilssan schematics.

Ken

I doubt if you're going to find the specific schematic for a Ilssan whatever. Open the case, and identify the regulator chip. Then, dig through the mess of schematics that Google finds and see if you can find a similar schematic that uses the same chip. You won't get the exact schematic but it will be close.

"Notes on the Troubleshooting and Repair of Small Switchmode Power Supplies"

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

[it] blew.

for

Try a photo posting place, like Flickr.com , PhotoBucket.com , or, if you don't want to register with the site, try TinyPic.com or ImageShack.us .

Really, really good FAQ about electronics repair:

Unplug the AC power cord before opening the power supply, and don't even test it unless its cover is fully installed (all screws tightened).

I'm no expert, but I've never seen a fusible resistor inside a common PC power supply, except maybe the large rectangular ceramic ones. Fusible resistors are more common on motherboards, near the ports for the keyboard, mouse, and USB, and on hard drives (usually next to a zener to protect against overvoltage, and if it triggers, the fuse associated with it pops). When regular resistors open up (higher than rated resistance), they usually show burn marks or cracks, but fusible resistors usually open up without showing damage.

The only coils that tend to burn in power supplies are those for the automatic power factor correction (high voltage side) and the output filters (low voltage side), and I think your problem is related to the latter because those coils run hot, and those coils vary a lot in size, depending not only on power ratings but also on the quality. If the affected coil is in the low voltage section, maybe you can separate its wires from one another in the burned area and coat them with varnish. Do NOT do this if the coil handles high voltage. Typically when a PC power supply fails and its fuse doesn't pop, the problem is in the low voltage section, such as a shorted diode or MOSFET or a worn electrolytic capacitor. Use only low-ESR capacitors for replacement, preferrably of the same diameter (tight fit in there). Any replacement diode or MOSFET has to be of the same type (diode should be Schottky) and meet the same minimum ratings for amps, volts, and watts. To remove anything attached to a heatsink, it's usually necessary to unsolder everything, including the heatsink.

Reepair.net/en or ElektroTanya.com may have something, but more likely you'll have to find the controller chips and rely on data sheets and applications notes from the makers of those chips. But generally, to fix an ATX power supply you just look for physical damage, bad solder joints, and check diodes and transistors with a meter.

I'm going to second, or is it third, or fourth, sentiments expressed by others.

A power supply has safety issues with it. Do something wrong, and it could burn down your house. How are you going to test it anyway? It probably won't run without a load? Attach it to your motherboard? Could be bye-bye MB.

Send it to the tip.

Sylvia.

You mean like this?

It was fairly impressive when it went off in my face. Fortunately, I was wearing glasses.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Yes, I've been glad to have been wearing safety glasses on occasion when bits of power transistor have attempted to go into orbit (UPS repair).

Sylvia.

[Q] What's the difference between a battery and an explosive? [A] Energy density. Batteries Lead Acid 150,000 Joules/Kg Li-Ion 460,000 Joules/Kg Lithium Thionyl Chloride 2,000,000 Joules/Kg Explosives TNT 4,700,000 Joules/Kg We're getting there with batteries.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Sure. Black powder engines work:

However, I prefer reactor grade uranium fuel at 3.7*10^12 Joules/Kg to power a UPS and vehicle.

The problem is that if you do find a way to rapidly discharge a battery, it has enough energy to create an impressive explosion. Power(watts) = Energy (Joules) / Time The faster you extract the energy, the bigger the bang.

In the late 1960's, I successfully did that with a crow bar across a

55 gallon drum oil bath capacitor (fusible wire high voltage switch). The crow bar didn't melt but the sound of the explosion shook the building, set off alarms, deafend me for about an hour, and caused a bulge in the can. With the latest Lithium-something battery technologies, a major advantage is that one can extract large amounts of current over a small interval. Most battery packs have circuits or fuses to prevent this from happening, but if you're working with the raw battery, the possibility of blowing something up is very real. This might be one reason why UPS manufacturers are still using lead-acid or AGM batteries, instead of going to Li-Ion mutations.

Of course, electric vehicle manufacturers have gone to some effort to make their battery packs safe (SAE 2464, 2929). However, if you bypass those safety features, you get a big bang.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Hi everyone,

Thanks for all your comments, links and photos.

Do not to confuse things so have started a new post "PC Power Supply Recommendations?"

Ken