PSUs _and_ any cooling devices spun by fan are prime troublemakers. Problems shows up in data corruptions, complex software crashes when system overheats whole or locally. Weak capacitors cause reboots or PSU cut outs. I have personally seen chips die from bad cooling for any causes if ingored too long. CPU is chip btw. I _did_ blow a PSU byproduct of multiple cycling 10 sec on, 2 sec off, so on...then it died after few cycles. Analysis showed single chopper TO-220 transistor on thin sheet of steel heatsink run by 8 pin PWM kickstarted by a 1W resistor to it, 3 bladed fan, 2 piece axial diodes one end soldered into piece of strip for heatsink. That psu went into bin shortly after. PSUs based on '494 and lm339 ICs compled with decent components especially 105C capacitors, good heatsinks, enough filter networks and ball bearing fan in PSU case with proper sized vents did very well. And cost difference is minimal. Major problem that I wondered anyone haven't noticed is that consumers DO only look at features AND cost. Oh, also consumer only assumed that all computers is created equal on parts because decent computer for 1100 using fewer features, good all-round cpu and OS, one or 2 s/w OR 1000 one with weaker ill-balanced cpu, crappy parts, highly mis and boatloads of "freebie" software and a OS, they usually commonly picks the latter. Or don't think about it, just results. NOT! Resposiblity starts with rsseller educating the buyers and only sell good ones only. Many will come to senses after going one or two mistakes with crappy vendors and go over to good reseller. Good wholesaler does matter much too. We were blessed with one good one. And few good resellers. Those stubborn bargin buyers are usually falls into 2 classes, one who have too little knowlege and pick one by mistake, and one who have just enough knowledge to be dangerous and have a say in everything. Wizard