Did I just compromise my computer? HELP!

[Jefferson]

Hey all, I'm nearing completion of my 2nd cab (a cocktail) and suddenly my PC is less stable-- freezing occasionally, getting 'usb connection found' and 'usb connection lost' sounds back and forth, and THE WORST, a 'hard drive spinning down' sound coming from within my pc.  Like its hard staying up and going.  I had to hard-shutdown once or twice so I've come to you for advice and understanding!

I suspect it started when I plugged in my first attempt at 'oscars' volume control, and while fumbling with the exposed wires and my crap solder, I must have touched the wrong two terminals on the pot and shorted something out.  Thats when the 'drive winding down' sound started.  Up and down it would wind, sending chills down my DIY spine.  I shut it down and restarted with out the knob and all seemed fine.  Even now its able to function normally for some periods, its just getting finicky.

I feel like my only options are:
-Back up all my mame/mala stuff
-Try running the speakers to the 'front' audio out jack instead of the one I possibly fried, in case the damage is isolated to that sound card

Has anyone else had this problem, is there a 'part' i can replace in my pc to fix this?  I'm a better builder than I am a computer guy! I'm fuh-reaking out!!!  So close!

[BobA]

Does your sound card still work with the volume control removed?    When you powered down did you disconnect the AC to the power supply or just turn off the computer.   Try pulling the AC plug out of your power supply and then powering it up again.   If your sound card has a problem then it would be a real good idea to remove it.

[Jefferson]

I removed the oscars volume knob hack right after the initial scare and went back to just the crappy computer speakers, which work fine (soundwise, aside from the general computer problems I detailed)

I just restarted (it may have been a hard shutdown) after the initial scare, and didn't unplug anything, inside or out.  Did you mean the AC adapter between the computer and the wall?  I'm generally wary of mucking around inside of a comp unless its something easy (wiring an arcade powerbutton, ram or an AVGA.)

I'm gonna try and fire her up again with the 360s in new USB plugs and the speakers in the front jack...

[Jefferson]

OK I unplugged and replugged the ac adapter, speakers and all usb (kbd, mouse, 2 360s)

It boots, goes to mala, preview videos are fine... and then they freeze and the drive winds down.  it winds back up and the preview videos start and stop.  I get a lot of usb found and usb lost noises. and then it just freezes, and I cant right click the mouse or ctrl alt del or safe shut down via power button.  My only option is hard shutdown.  Help!  I will keep experimenting (next up... no speakers) but I'm afraid if I have to keep shutting down hard I'm just making it worse!

[Jefferson]

Still freezes in mala without 360s or speakers plugged in. ahhhh

[BobA]

Unplug everything USB and see if the problems stop.   If they do not I would try a new PS or one from another computer if possible. 

[GibsonRiddler]

Back up all your mame/mala stuff anyway just to be safe.

[drventure]

Sounds like you may have shorted something, and pushed the Powersupply to the edge.

The harddrive spinup spin down, is not good. Could be the HD, though it's more likely that the rails from the PS have been compromised.

If you have another PS lying around, I'd swap it out or use a PS Tester on the one you've got.

That's where I'd start.

Then, I'd likely disconnect EVERYTHING, and start reconnecting one at a time, and just leave the machine in that state to see if it stays stable.

Those kind of problems suck. Sorry to hear it.

[whines]

Yeah, I'd consider a bad powersupply as a possibility. Bad PS's cause all sorts of bizzare problems.

[Jefferson]

Alright I will start by identifying the existing power supply and finding a new similar... I will probably have more questions as I dig deeper... thanks so much guys!

On the bright side, this might get me to decase and mount my PC inside the cab...

[Jefferson]

I bought a new power supply (like a 450 W) and I no longer have the hard drive spin up-spin down... I'm back in action (although I do get the very occasional MALA freeze... it may be due to some other kinks I have to iron out (I soldered the midway start buttons as normally-closed accidentally.)

Thanks everyone for your help.  The PS switch out was easy and educational.  I followed this tutorial:
http://www.hardwaresecrets.com/article/362

[Jefferson]

Well, a few more problems have arisen and I don't know if they're related.

- maybe one in ten times, my PC will freeze and I'll have to hard-shutdown.  Sometimes its in Mala, once it was before mala booted, once it was during play
- After a few minutes, most games have a glitchy sound quality, with roms I swear I didn't have this problem before... pausing and unpausing seems to alleviate it for a while then it starts again.
- sometimes during gameplay everything will hang up for one second and ill hear the fan turn on or off.  Not major, but it freaks me out thinking I'm gonna have to restart.

Unrelated:

Is there a way to tell mame to run d3d or ddraw for specific roms or does it take running multiple versions?  I like my classics running ddraw.  much crisper.

[JustMichael]

Is the pc currently in the cocktail or still sitting outside?  If it is inside the cocktail, is there too much heat building up?

[Jefferson]

Its inside the cocktail with the side panel off of the pc case... its warm, but I hadnt found much in the forums to convince me that fans and venting were really necessary...  I'll fire it up with the coin door open for a while and see if that helps.  The sound thing is really whats bothering me.