PSU fried drive, but whose fault was it?

I bought a barebone system a few weeks back that came with an ULTRA brand 500w PSU and Sony DVD-ROM. Assembled it and tested her out for a few days -- all was good. The PSU however never lost it's new electronic smell (this may be relevant later).

Last week I decided to do some mods, beginning with sleeving the PSU cables. I was very careful and systematic, ensuring that everything was reassembled properly. I was in no rush and after a couple days finished the job.

Today I planted the PSU back in my system and gave her a boot. It locked at the "Detecting IDE Drives" message. It took removing both the HD and DVD-ROM for it to get beyond this stage. I tested the HD and DVD-ROM on my old system; HD was fine, but the DVD-ROM caused even this system to now lock at boot.

Initially I assume the DVD-ROM just died, so I test an old Sony 4x CD-ROM on the old system (checks out okay) and then plug it into my new modded system. When I turn the system on, the CD-ROM immediately goes Rice Krispies (snap crackle pop) and smoke appears. UGH.

Which brings me to my dilemma. Where is the problem? It's easy to suggest I screwed something up while modding the PSU (which I won't discount), but I feel confident in the job I did. The PSU itself certainly isn't fried, at the fans still spin, lights turn on, and I can enter CMOS. If the PSU fried the DVD/CD-ROM, then why is the HD fine? Is it too unlikely that the DVD-ROM merely went bad and the 4x CD-ROM couldn't handle a 500w PSU, meaning the PSU is actually fine?

I'm nervous to plug any drives back into the PSU, even though it still appears to be fine. I'm really stumped on this one -- any advice??

 

When you sleeved the wires coming from the PSU did this require you to remove the molex connector shouds, if so when you reassembled them you may have switch the +5V lead for the +12V lead the the peripheral power connector pin out (flat side down) is +12V com com +5V test the connector with a multimetor for position.

 

Well I gotta hand it to ya, you nailed that one! I did indeed remove the molex connectors while sleeving and would have bet my soul that I'd reattached them properly... but low and behold, while attempting to verify the voltage with my new multimeter, I had the +12V and the +5V swapped.

Anyway, all's been corrected now and I can use the machine like normal... well minus a DVD and CD-ROM, that is . Would you say there's need for concern for any other components now (PSU, mobo?), because of the whole frying experience?

lol, and I supposed these two drives now are only good for hood ornaments.

 

Usually the circuit board has a small burn on it where it fried. Essentially the circuit board acts as a fuse. Very easily fixed if you are handy with a soldiering gun

 

There is a very slight chance of other components frying, and if they did they would not be working at the same time the drive died, however you did learn a very valuable lesson always have the pin outs for any multiple pin configurations and double check every thing before committing to it. As far as the dead drives are concerned if they are still under warranty you can always return them, if not and your really good with a soldering iron you can replace the overload diodes.