Blown Motherboard from ATA-100 Cables?

Dragan Lazin asks: "I recently bought a couple of rounded ATA-100 cables from an online store; very ingenious actually and they have a nice color: blue ;-) Problem is, when I installed the cables, 16 capacitors on my motherboard blew - right between the CPU and the parallel port header. This is an Abit KA7-100 mobo. What the hell causes this kind of damage? I'm trying to get a refund and a new mobo from the company. Did anyone ever experience this?"

Comments

A short?

[kurtras]

I don't know how the cables go from short to round, could the rounding process have caused a short? Do you know if the capacitors had anything to do with the IDE bus, or could they be unrelated?

Re:A short?

[SagSaw]

I haven't seen the ThinkGeek round cables up close, but you can buy round ribbon cable. The ribbon cable comes from the manufacturer folded up inside a round outer jacket. I suspect this is what the round IDE cables are made out of. Hopefully, the cable would have been somewhat tested by the manufacturer (both of the raw cable and of the IDE cable assemblies), so there shouldn't been any "preexisting conditions".

Bad Cable, Bad Board?

[RadioheadKid]

Had you used the board before trying out the round cables? If so, the most logical explaination is a bad cable...It does happen, a bad crimp or solder can easily cause a short.

KidA

Re:Bad Cable, Bad Board?

[discoinferno]

There isn't enough voltage or current in those cables to blow a cap off of a motherboard. We are talking about high/low signalling. Likely on the order of 20 to 50mA tops. Even beyond that, there are no capacitors connected directly to the IDE signalling lines.

How do we blow up caps? 1) power up a tantulum cap backwards. Not possible with a bad IDE cable for the reason above... no caps connected to the lines. 2) apply a huge voltage to a low voltage capacitor. Likely the caps on a motherboard are around 6.3V caps, so this is possible. But again, there are no caps on the IDE lines. Not gonna happen.

Hence, blowing caps off of the motherboard (assuming that it actually did happen...) was not caused by the cables. The only was to possibly do this was to plug in your cables from the powersupply to the motherboard wrong. In this case, it is possible to get GND and +V backwards in this case.

Don't blame the cables, blame user stupidity.

Actually, I doubt that this is even a real question. Sounds more like a troll that got posted by Cliff.

Re:Bad Cable, Bad Board?

[ivan256]

Well, on a cheap motherboard, it could be possible that the IDE's V+ and ground aren't regulated seperatly from the main power regulator on the board. A short across the two could cause the power regulator to heat up very quickly, and the radient heat could spell trouble for the nearby caps. I can't imagine that it would all happen instantly though. There also could be a problem with the drive that would cause the 12 volt power to short to ground. That would reverse the polarity on lower voltage caps. This is all a long shot though, and I'd be surprised if all that was new in the setup was the cables.

How would a cable make capacitors blow up?

[hamjudo]

Some how, 12 or more volts has been shorted onto the 3.3 or 5 volt supply. If you look closely at the motherboard, you'll probably see heat damage around one trace on the motherboard. You may even be able to see where the damage starts. Look for a loose screw or metal trash underneath the motherboard.

Capacitors blow up from too much heat, which for a DC power supply filtering capacitor implies too much voltage. Capacitors are in parallel with the power supply. Something put too high a voltage across the capacitors.

Unless I'm really confused, the highest voltage on the IDE connector is only 5 volts, and all of the pins on the IDE connector are either ground or are compatible with 5 volts. You can hurt the logic chips and the power supply by shorting stuff on the IDE connector, but you won't blow up the capacitors.

Re:What kind are they?

[msaavedra]

Been wondering why they weren't rounded earlier

The reason ide cables have traditionally been ribbon-shaped is to minimize cross-talk. Perhaps the round cables use some sort of pair-twisting scheme, or maybe they use shielding. Or perhaps they just decided that cross-talk wasn't really as much of a problem as the engineers originally thought.

Re:What kind are they?

[dafoomie]

I was thinking about that, but then I thought about all the other cables that were rounded before. Seems logical... IDE cables probably transfer more data and have a higher propensity for crosstalk. I guess they fixed that. But you could just take some rubber bands and round ribbon cables yourself and not cause problems, all you need to do to make those is put some rubber around it.

Re:The Cables caused the Problem?!?

[Bryan Andersen]

I could possibly, but not likely, see it happening if two failures happened at the same time. Lack of ground to the IDE drive through it's power connector[1], and hooking up the IDE cable wrong. It would still likely not happen. My guess is you dropped something on the motherboard that shorted the +12DC supply to the CPU's Supply or knocked off the voltage control jumpers[2] for the CPU voltage(s).

[1] The pin/socket style used on most HD power connectors isn't that good. It tends to get weaker with every use and fails after only a few hundred cycles. It will also fail faster if it isn't aligned right and you force it. This could cause the ground and +5VDC lines to not connect up properly. Thus the drive would be biased at +12V.

[2] Removing, knocking off the voltage control jumpers or putting them into an undefined state may make the switching power supply that feeds the caps to go over voltage. This could also destroy the cpas.

Not sure if this would help...

[cr0sh]

I somehow doubt the cable had anything to do with it - other people's postings here seem to reflect this, and also give many good tips/ideas as to what happened.

One thing to consider, though, is whether the parallel port controller chip also is the IDE controller as well - sometimes motherboard manufacturers use these "super"-chips as a means to cut costs. I am involved in a group "hacking" the Acer NT-150 set-top box, and the controller chip for the parallel port on it also has some IDE controller functions, as well as floppy drive functions. Basically, they made it so you could build a "funky" parallel cable, hook it up to a floppy drive, plug the other end into the parallel port, and that becomes the floppy port - otherwise it is for a printer.

There may be a connection in your case - who knows?

This sort of thing just happened to me

[OnyxRaven]

I have an ABIT KA7 (not -100) that blew all the capacitors on the processor side of the board. I still havent figured it out exactly, but I guessed that it was a combination of maybe over-overclocking without sufficient cooling, or when I plugged in my printer it had a bad ground. That or it was just a nice random occurance to make me go and spend money :-).

Not certain on either one, but it made me buy a new board and processor (and ram... DDR is god) and now I dont use my printer any more because I really dont want to fry this one.

More or less, the things that others have said about the rounded cables not being the problem are probably right. Not nearly enough voltage to blow all those caps.

Oh well. I havent tested out my processor to see if it is still okay yet. I want to use it for a server so I hope it is.

Re:This sort of thing just happened to me

[Helix150]

wow... the exact same thing happened to me. Except I was installing a GeForce3... (asus v8200)

It went in OK, but would not switch to VR mode (it has goggles). I tweaked the drivers and rebooted, it wouldnt boot. Safe mode and VGA mode died soon after, and then it wouldnt boot from Win2k CD. So I figure bad card, replace it. When I open the case I see one of the caps near the DIMM slots was on an angle, I figured I kicked it plugging something in. But when I pull the card (w/ everything unplugged, myself grounded), I hear a short hiss. Examination with a flashlight shows 3 caps near the CPU have popped (off base at angle with burnt stuff below, curved top), and the one I saw earlier has completely blown off its base and theres burnt black rubber stuff around it and the one next to it.

I was looking for an excuse to get a KG7, and this works, although it wasn't what I had in mind

If anyone cares, the blown ones are:

By CPU, 1500uF, rated at 6.3v, 105C: 3 blew, cant see markings. From the top, 2nd, 3rd and 6th in the row next to the SlotA

And by DIMMs, a 2200uF 6.3V 105C, right next to DIMM1, top in a group of two.

All are JPCON

Who did Abit buy the capacitors from?

[unitron]

Sometimes electrolytics go bad just because they go bad, the dielectric gets punctured (electrically) at an unforseen weak spot, shorting the high side to ground, current flows, genereates heat, and the thing goes bang and swells up or blows off part of the can.

Seeing as how we've got at least 3 Abit owners posting this problem so far, and not all are using ATA-100 round cables, I'd suspect that Abit got a bad run of caps from their subcontractor, although some sort of voltage regulator problem that fed those caps too much voltage or let a reverse polarity spike get through to them could also be at fault. Are all of y'all using the same brand power supply?

Gnnn. Can't... resist... suggesting...

[Rogerborg]

...that this is an "undocumented feature" of WinXP hardware product verification. >>> ;-) <<<